Literatura académica sobre el tema "Pannes byzantines"

Chemical composition of 39 window panes of the Early and Middle Byzantine periods was studied with SEM-EDS technique. They originate from the Gorzuvity settlement in the Crimea Southern coast with the ruins of two churches, and Mangup, the largest medieval fortress in the SW Crimea. The presence of glass of groups Foy-3.2/2.1 and HIMT suggests that the earliest structures with glazed windows could have emerged on Mangup in the 5th century at the latest — i. e., before the construction of the Byzantine fortress. A homogenous composition of glass from Gorzuvity suggests a single period of glazing windows of structures existing here — the “lower” church with a shrine dated probably to the 11th century (terminus ante quem for the church construction) and some stone structures at the settlement. 37 samples represent natron glass of the Egyptian origin. Most of window panes are related to the 9th—10th/11th cc. Their glass belongs to the series Foy-2.2, the result of the recycling of the earlier glass of the 2nd half of the 5th/6th — mid-7th centuries (series Foy-2.1). It suggests that the remains of monumental structures of the early Byzantine period (window panes and probably tesserae) were used as raw materials during the construction campaign at Gorzuvity and Mangup in the middle Byzantine period. Two fragments from Mangup of mixed-alkali composition originate from the contexts of the 15 th c., where they could get from disturbed earlier deposits.

The excavations conducted starting with 2010 in the Centre-North Sector from Histria/Istros (Romania) brought to light, among other finds, a series of glass fragments, the most numerous belonging to window panes and goblets. The last mentioned group of finds can be attributed to Isings form 111, stemmed goblets with folded base. This paper is part of a series of publications focused on the publication of the items belonging to this widespread type of vessel of the Late Roman/Early Byzantine period (5th-7th centuries AD), found on the Centre-North Sector.

ABSTRACTFrom the early eighth century CE Byzantine shops next to the Synagogue and Bath-Gymnasium Complex at Sardis, Turkey, were excavated from 1958 to 1969 more than 50 pounds, or about 350 panes of transparent flat glass sheets interpreted as window glass. Examination using optical microscopy showed little variation in size, shape, thickness, edge shape, tool marks, bubble and cord elongation and alignment. Microstructural and compositional variation of weathered surfaces and unweathered cross sections were studied using scanning electron microscopy with energy dispersive x-ray analysis (SEM-EDS). Differential thermal analysis (DTA) was used to determine glass transition temperature range. Three traditional window-forming methods have been described in the glass technology literature: crown, plate and cylinder. The Sardis glass is most similar to criteria expected for cylinder glass, but significant differences were documented. Consistently patterned characteristics evidence a developed technological practice. Replicative tests were conducted using various forming sequences. Wooden and ceramic two-piece molds were made to overblow one or both ends, and hot glass threads were used to thermal shock the cylinder ends and to make a vertical crack that allowed opening during a reheating and slumping operation. These reconstructed methods fit the observed microstructural and macrostructural characteristics of the glass sheets. Analysis of glass manufacturing methods in antiquity contribute to the historical knowledge of craft practices and to the interpretation of industrial debris excavated at markets and industrial workshops.

Saint Canute the King’s Eagle Cloth in Odense CathedralA new interpretation The eagle silk cloth in Odense Cathedral (Fig. 1) is believed to have been part of the contents of the shrine of Saint Canute (King Canute the Holy); it was perhaps a cape used as a shroud. Today it measures 110 by 133 cm, but originally it was larger, at least 130 by 195 cm. The purple fabric with its blue-black eagle pattern and decoration is generally regarded as a “pannus imperialis ad aquilas magnas” – a term known from medieval texts. The style of its decorative motifs dates it to the 11th or 12th century. Otto von Falke regarded the Odense cloth and related fabrics as the products of the Byzantine state workshop. Agnes Geijer, on the other hand, assumed that the Odense specimen was made by Islamic weavers in Southern Italy or Sicily and that it had formed part of the gifts which Canute’s widow, who had later married Duke Roger of Apulia, sent to the saint’s shrine.Underneath the eagle pattern on the cloth there seems to be an inscription (Fig. 2). Although only a few of the letters are legible the classical philologist Carsten Høeg considered them to be based on Greek letter-forms. It is in fact possible to distinguish at least five, and in addition, there are some possible ligatures of two or three letters (Fig. 3). A comparison between these vestiges and well-known By­zantine textile inscriptions leads to the impression that the last word could have been DESPOTOU, and that several of the preceding signs may be part of the word PHILOCHRISTOU. If so, we have an official dating, and even the name of the emperor in question. Among the rulers in the 11th and the 12th centuries, only five had a name short enough to fit into this context, and if we are right in distinguishing an alpha or a lambda in the beginning, this would exclude all but Alexios. Consequently, we will venture to make a hypothetic reconstruction with this name based on the existing remains (Fig. 4).The style of the fabric makes it most unlikely that anyone else but Alexios I (1081-1118) could come into question. It was he, who – probably in 1103 – received Saint Canute’s brother, King Eric the Good (Erik Ejegod), who died that very same year in Cyprus on his way to the Holy Land. In Eiriksdrapa, the memorial poem written in honour of this king by the contemporary Icelandic bard, Markus Skeggjason, it is explicitly stated that among other rich gifts, Eric was presented with an imperial garment: “allvalds skruði”, i.e. “the emperor’s shroud”.One of the present authors has drawn attention to the possibility that the bluish dark colour of the eagles indicates that the fabric was intended for a “sebastokrator,” a brother or son of the emperor or someone else very close to him. The colours, the ­eagles, and the size of the cloth would actually be appropriate for the type of garment called a “paludamentum”, a purple officer’s cloak worn by the emperor and other highly prominent persons (Figs. 5-6). Some of the leaders of the First Crusade were honoured by being elevated to the status of adopted sons of the emperor, and Krijnie Ciggaar has wondered whether the same could have happened to Eric. If this was the case, then it seems that it was Eric’s imperial silk cloth that was transferred to Odense as a tribute to his more distinguished brother, the martyr saint.Recently, it has been stated that the red colour of the Odense cloth is not genuine purple. However, the loss of most of Anatolia and Lebanon made it difficult for Byzantine workers to obtain the right colour components. Genuine murex-purple was in fact used in Constantinople until the thirteenth century, but this top-quality purple was reserved for the emperor alone. This explains why an inferior dye quality was used for the Odense cloth, which was made for a person with the rank of a seba­stokrator.P.J. RiisKøbenhavnThomas RiisChristian-Albrechts-Universität zu Kiel

Une communication fiable est une primitive fondamentale dans les systèmes distribués sujets aux pannes Byzantines (c'est-à-dire arbitraires et éventuellement malveillants) pour garantir l'intégrité, l’authenticité et la livraison des messages échangés entre les processus. Son adoption pratique dépend fortement des hypothèses du système. Plusieurs solutions ont été proposées jusqu'à présent dans la littérature mettant en œuvre une telle primitive, mais certaines manquent d'évolutivité et / ou exigent des conditions de réseau topologiques difficiles à vérifier. Cette thèse vise à étudier et à résoudre certains des problèmes et défis ouverts implémentant une telle primitive de communication. Plus précisément, nous analysons comment une primitive de communication fiable peut être implémentée dans 1) un système distribué statique où un sous-ensemble de processus est compromis, 2) un système distribué dynamique où une partie des processus est Byzantiné, et 3) un système distribué statique où chaque processus peut être compromis et récupérer. Nous définissons plusieurs protocoles plus efficaces et nous caractérisons des conditions de réseau alternatives garantissant leur exactitude<br>Reliable communication is a fundamental primitive in distributed systems prone to Byzantine (i.e. arbitrary, and possibly malicious) failures to guarantee the integrity, delivery, and authorship of the messages exchanged between processes. Its practical adoption strongly depends on the system assumptions. Several solutions have been proposed so far in the literature implementing such a primitive, but some lack in scalability and/or demand topological network conditions computationally hard to be verified. This thesis aims to investigate and address some of the open problems and challenges implementing such a communication primitive. Specifically, we analyze how a reliable communication primitive can be implemented in 1) a static distributed system where a subset of processes is compromised, 2) a dynamic distributed system where part of the processes is Byzantine faulty, and 3) a static distributed system where every process can be compromised and recover. We define several more efficient protocols and we characterize alternative network conditions guaranteeing their correctness

La Tolérance aux pannes Byzantines (BFT) est de plus en plus crucial avec l'évolution d'applications et en raison de la croissance de l'innovation technologique en informatique. Bien que des dizaines de protocoles BFT aient été introduites dans les années précédentes, leur mise en œuvre ne semble pas satisfaisant. Pour faire face à cette complexité, due à la dependence d'un protocol d'une situation, nous tentons une approche qui permettra de sélectionner un protocole en fonction d'une situation. Ceci nous paraît, en s'inspirant de tout système d'encrage, comme une démarche nécessaire pour aborder la problématique de la BFT. Dans cette thèse, nous introduisons un modèle de sélection ainsi que l'algorithme qui permet de simplifier et d'automatiser le processus d'élection d'un protocole. Ce mécanisme est conçu pour fonctionner selon 3 modes : statique, dynamique et heuristique. Les deux derniers modes, nécessitent l'introduction d'un système réactif, nous ont conduits à présenter un nouveau modèle BFT : Adapt. Il réagit à tout changement et effectue, d'une manière adaptée, la commutation entre les protocoles d'une façon dynamique. Le mode statique permet aux utilisateurs de BFT de choisir un protocole BFT en une seule fois. Ceci est très utile dans les services Web et les " Clouds " où le BFT peut être fournit comme un service inclut dans le contrat (SLA). Ce mode est essentiellement conçu pour les systèmes qui n'ont pas trop d'états fluctuants. Pour ce faire, un processus d'évaluation est en charge de faire correspondre, à priori, les préférences de l'utilisateur aux profils du protocole BFT nommé, en fonction des critères de fiabilité et de performance. Le protocole choisi est celui qui réalise le meilleur score d'évaluation. Le mécanisme est bien automatisé à travers des matrices mathématiques, et produit des sélections qui sont raisonnables. D'autres systèmes peuvent cependant avoir des conditions flottantes, il s'agit de la variation des charges ou de la taille de message qui n'est pas fixe. Dans ce cas, le mode statique ne peut continuer à être efficace et risque de ne pas pouvoir s'adapter aux nouvelles conditions. D'où la nécessité de trouver un moyen permettant de répondre aux nouvelles exigences d'une façon dynamique. Adapt combine un ensemble de protocoles BFT ainsi que leurs mécanismes de commutation pour assurer l'adaptation à l'évolution de l'état du système. Par conséquent, le "Meilleur" protocole est toujours sélectionné selon l'état du système. On obtient ainsi une qualité optimisée de service, i. E. , la fiabilité et la performance. Adapt contrôle l'état du système grâce à ses mécanismes d'événements, et utilise une méthode de "Support Vecor Regrssion" pour conduire aux prédictions en temps réel pour l'exécution des protocoles (par exemple, débit, latence, etc. ). Ceci nous conduit aussi à un mode heuristique. En utilisant des heuristiques prédéfinies, on optimise les préférences de l'utilisateur afin d'améliorer le processus de sélection. L'évaluation de notre approche montre que le choix du "meilleur" protocole est automatisé et proche de la réalité de la même façon que dans le mode statique. En mode dynamique, Adapt permet toujours d'obtenir la performance optimale des protocoles disponibles. L'évaluation démontre, en plus, que la performance globale du système peut être améliorée de manière significative. Explorer d'autres cas qui ne conduisent pas de basculer entre les protocoles. Ceci est rendu possible grâce à la réalisation des prévisions d'une grande precision qui peuvent atteindre plus de 98% dans de nombreux cas. La thèse montre que cette adaptabilité est rendue possible grâce à l'utilisation des heuristiques dans un mode dynamique<br>Byzantine Fault Tolerance (BFT) is becoming crucial with the revolution of online applications and due to the increasing number of innovations in computer technologies. Although dozens of BFT protocols have been introduced in the previous decade, their adoption by practitioners sounds disappointing. To some extant, this indicates that existing protocols are, perhaps, not yet too convincing or satisfactory. The problem is that researchers are still trying to establish 'the best protocol' using traditional methods, e. G. , through designing new protocols. However, theoretical and experimental analyses demonstrate that it is hard to achieve one-size-fits-all BFT protocols. Indeed, we believe that looking for smarter tac-tics like 'fasten fragile sticks with a rope to achieve a solid stick' is necessary to circumvent the issue. In this thesis, we introduce the first BFT selection model and algorithm that automate and simplify the election process of the 'preferred' BFT protocol among a set of candidate ones. The selection mechanism operates in three modes: Static, Dynamic, and Heuristic. For the two latter modes, we present a novel BFT system, called Adapt, that reacts to any potential changes in the system conditions and switches dynamically between existing BFT protocols, i. E. , seeking adaptation. The Static mode allows BFT users to choose a single BFT protocol only once. This is quite useful in Web Services and Clouds where BFT can be sold as a service (and signed in the SLA contract). This mode is basically designed for systems that do not have too fuctuating states. In this mode, an evaluation process is in charge of matching the user preferences against the profiles of the nominated BFT protocols considering both: reliability, and performance. The elected protocol is the one that achieves the highest evaluation score. The mechanism is well automated via mathematical matrices, and produces selections that are reasonable and close to reality. Some systems, however, may experience fluttering conditions, like variable contention or message payloads. In this case, the static mode will not be e?cient since a chosen protocol might not fit the new conditions. The Dynamic mode solves this issue. Adapt combines a collection of BFT protocols and switches between them, thus, adapting to the changes of the underlying system state. Consequently, the 'preferred' protocol is always polled for each system state. This yields an optimal quality of service, i. E. , reliability and performance. Adapt monitors the system state through its Event System, and uses a Support Vector Regression method to conduct run time predictions for the performance of the protocols (e. G. , throughput, latency, etc). Adapt also operates in a Heuristic mode. Using predefined heuristics, this mode optimizes user preferences to improve the selection process. The evaluation of our approach shows that selecting the 'preferred' protocol is automated and close to reality in the static mode. In the Dynamic mode, Adapt always achieves the optimal performance among available protocols. The evaluation demonstrates that the overall system performance can be improved significantly too. Other cases explore that it is not always worthy to switch between protocols. This is made possible through conducting predictions with high accuracy, that can reach more than 98% in many cases. Finally, the thesis shows that Adapt can be smarter through using heursitics

Cette thèse de doctorat se compose de 6 chapitres. Dans le premier chapitre, en guise d'introduction, nous donnons un aperçu des objectifs généraux et des motivations des réseaux décentralisés et permissionless, ainsi que des obstacles auxquels ils sont confrontés. Dans l'introduction, nous évoquons également la solution irrationnelle et illogique, connue sous le nom de « blockchain permissioned », qui a été proposée pour améliorer les performances des réseaux similaires à Bitcoin. Cette question a été détaillée au chapitre 5. Dans le chapitre 2, nous rendons clairs et intelligibles les systèmes que l'idée proposée, « Parallel Committees », est basée sur de tels réseaux. Nous détaillons les fonctionnalités indispensables et les défis essentiels des systèmes de réplication. Ensuite, dans le chapitre 3, nous discutons des limitations de scalabilité et du faible débit des systèmes de réplication qui utilisent des mécanismes de consensus pour traiter les transactions et comment ces problèmes peuvent être améliorés en utilisant des techniques de sharding. Nous décrivons les défis les plus importants dans le sharding des systèmes de réplication distribuée, une approche qui a déjà été mise en œuvre dans plusieurs systèmes de réplication basés sur la blockchain et, bien qu'elle ait montré un potentiel significatif pour améliorer les performances et la scalabilité, les techniques de sharding actuelles ont encore des limitations de scalabilité et des défis de sécurité. Nous expliquons pourquoi la plupart des protocoles de sharding actuels utilisent une approche d'allocation aléatoire pour distribuer les nœuds entre les shards pour des raisons de sécurité. Nous décrivons également comment traiter une transaction dans un système de réplication partitionné basé sur les protocoles de sharding actuels. Nous expliquons comment un « shared-ledger » partagé sur les shards impose des limitations de scalabilité et des défis de sécurité au réseau, et expliquons pourquoi les transactions « cross-shards » ou « inter-shards » sont indésirables et plus coûteuses en raison des problèmes qu'elles causent, y compris « atomicity failure » et les défis de « state transition », ainsi qu'une passe en revue des solutions proposées. Nous passons également en revue certains des travaux récents les plus remarquables qui utilisent des techniques de sharding pour les systèmes de réplication. Cette partie de l'ouvrage a été publiée sous la forme d'un chapitre de livre (peer-reviewed) in « Building Cybersecurity Applications with Blockchain Technology and Smart Contracts » (Springer, 2023). Dans le chapitre 4, nous proposons une nouvelle technique de sharding, « Parallel Committees », prenant en charge à la fois le « processing-sharding » et le « storage/state sharding », pour améliorer la scalabilité et les performances des systèmes de réplication distribués qui utilisent des mécanismes de consensus pour traiter les demandes des clients (client requests). Nous introduisons une approche innovante et originale pour répartir les nœuds entre les shards à l'aide d'un processus de génération de clé publique qui atténue simultanément l'attaque Sybil et sert de mécanisme de preuve de travail (proof-of-work). Notre approche réduit efficacement les transactions « inter-shards » indésirables, qui sont plus complexes et coûteuses à traiter que les transactions « intra-shards ». L'idée proposée a été publiée dans la conférence IEEE BCCA 2023. Nous expliquons ensuite pourquoi nous n'utilisons pas la structure de la blockchain dans l'idée proposée, un sujet abordé en détail au chapitre 5. Cette explication et clarification a été publiée dans le Journal of Software (JSW), Volume 16, Number 3, May 2021. Et dans le dernier chapitre de cette thèse, le chapitre 6, nous résumons les points importants et les conclusions de cette recherche<br>This PhD thesis consists of 6 Chapters. In the first Chapter, as an introduction, we provide an overview of the general goals and motives of decentralized and permissionless networks, as well as the obstacles they face. In the introduction, we also refer to the irrational and illogical solution, known as "permissioned blockchain" that has been proposed to improve the performance of networks similar to Bitcoin. This matter has been detailed in Chapter 5. In Chapter 2, we make clear and intelligible the systems that the proposed idea, Parallel Committees, is based on such networks. We detail the indispensable features and essential challenges in replication systems. Then in Chapter 3, we discuss in detail the low performance and scalability limitations of replication systems that use consensus mechanisms to process transactions, and how these issues can be improved using the sharding technique. We describe the most important challenges in the sharding of distributed replication systems, an approach that has already been implemented in several blockchain-based replication systems and although it has shown remarkable potential to improve performance and scalability, yet current sharding techniques have several significant scalability and security issues. We explain why most current sharding protocols use a random assignment approach for allocating and distributing nodes between shards due to security reasons. We also detail how a transaction is processed in a sharded replication system, based on current sharding protocols. We describe how a shared-ledger across shards imposes additional scalability limitations and security issues on the network and explain why cross-shard or inter-shard transactions are undesirable and more costly, due to the problems they cause, including atomicity failure and state transition challenges, along with a review of proposed solutions. We also review some of the most considerable recent works that utilize sharding techniques for replication systems. This part of the work has been published as a peer-reviewed book chapter in "Building Cybersecurity Applications with Blockchain Technology and Smart Contracts" (Springer, 2023). In Chapter 4, we propose a novel sharding technique, Parallel Committees, supporting both processing and storage/state sharding, to improve the scalability and performance of distributed replication systems that use a consensus to process clients' requests. We introduce an innovative and novel approach of distributing nodes between shards, using a public key generation process that simultaneously mitigates Sybil attack and serves as a proof-of-work mechanism. Our approach effectively reduces undesirable cross-shard transactions that are more complex and costly to process than intra-shard transactions. The proposed idea has been published as peer-reviewed conference proceedings in the IEEE BCCA 2023. We then explain why we do not make use of a blockchain structure in the proposed idea, an issue that is discussed in great detail in Chapter 5. This clarification has been published in the Journal of Software (JSW), Volume 16, Number 3, May 2021. And, in the final Chapter of this thesis, Chapter 6, we summarize the important points and conclusions of this research

La prolifération des véhicules autonomes a imposé la nécessité d'une gestion plus sécurisée des données du trafic routier (c'est-à-dire les événements liés aux accidents, l'état de la circulation, le rapport d'attaque, etc.) dans les réseaux Ad hoc pour véhicules (VANET). Les systèmes centralisés traditionnels répondent à ce besoin en exploitant des serveurs distants éloignés des véhicules. Cette solution n’est pas optimale, car les données relatives au trafic routier doivent être distribuées et mises en cache de manière sécurisée à proximité des véhicules. Cela améliore la latence et réduit la surcharge sur la bande passante du réseau de communication.La technologie Blockchain est apparue comme une solution prometteuse grâce à sa propriété de décentralisation. Certaines questions restent néanmoins sans réponse. Comment concevoir une validation appropriée des données du trafic routier par blockchain, qui semble plus complexe qu'une transaction financière ? Quelles sont les performances attendues dans les scénarios VANET ?Cette thèse offre des réponses à ces questions en concevant une gestion des données du trafic routier adaptée aux contraintes imposée par la blockchain. La performance ainsi que la validité des protocoles proposés sont ensuite évaluées à travers diverses simulations de scénarios pris d’un trafic routier réel.Nous proposons d'abord une adaptation du mécanisme de consensus Preuve de Travail (PoW) dans un réseau VANET, où les infrastructures situées aux bords de routes (RSUs) maintiennent une base de données décentralisée des données du trafic routier. Ensuite, une évaluation rigoureuse des performances en présence de véhicules malveillants est réalisée. Les résultats ont montré que le schéma proposé permet de construire une base de données sécurisée et décentralisée des données du trafic routier au niveau des RSUs.Ensuite, motivés par nos résultats, nous utilisons PBFT (Practical Byzantine Fault Tolerance), un mécanisme de consensus établi grâce au vote, pour réduire la latence dans le processus de validation dans une blockchain. Les RSUs validatrices de données de trafic sont sélectionnées dynamiquement en fonction de la localisation des événements du trafic. Nous proposons un nouveau schéma de réplication de la blockchain entre les RSUs. Cette réplication choisit un compromis entre les performances en termes de latence et la fréquence de réplication des blocs de la chaine. Les résultats de simulation montrent de meilleures performances, lorsque les RSUs validatrices, sont réduites au minimum.Dans la dernière partie de la thèse, nous proposons un modèle de confiance pour réduire au minimum le nombre de validatrices sans compromettre la décentralisation et l'équité de la création de blocs. Ce modèle de confiance s'appuie sur la distance géographique et la confiance des RSUs pour former dynamiquement un groupe de validateurs pour chaque bloc de la chaîne. Nous formalisons et évaluons ce modèle de réputation, en considérant divers scénarios avec des RSUs malicieuses. Les résultats démontrent l'efficacité de la proposition pour minimiser le groupe de validateurs tout en isolant les RSUs malicieuses<br>The prominence of autonomous vehicles has imposed the need for more secure road traffic data (i.e., events related to accidents, traffic state, attack report, etc.) management in VANET (Vehicular Ad hoc NETworks). Traditional centralized systems address this need by leveraging remote servers far from the vehicles. That is not an optimal solution as road traffic data must be distributed and securely cached close to cars to enhance performance and reduce bandwidth overhead. Blockchain technology offers a promising solution thanks to its decentralization property. But some questions remain unanswered: how to design blockchain-adapted traffic data validation, which is more complex than an economic transaction? What is the performance in real-world VANET scenarios?This thesis addresses those questions by designing blockchain-adapted traffic data management. The performance analysis and the validation of the proposed schemes are conducted through various simulations of real scenarios.We first adapt the PoW (Proof of Work) consensus mechanism to the VANET context whereby the RSUs (Road Side Units) maintain the decentralized database of road traffic data. After that, the proposed scheme is evaluated in the presence of malicious vehicles. The results show that the proposed approach enables a secure and decentralized database of road traffic data at the RSUs level.Next, motivated by our findings, we adopt PBFT (Practical Byzantine Fault Tolerance), a voting-based consensus mechanism, to reduce the blockchain latency. The traffic data validators are dynamically selected based on traffic event appearance location. Finally, we propose a novel blockchain replication scheme between RSUs. This scheme offers a trade-off between the blockchain latency and replication frequency. Simulation results show better performance when the validators (i.e., RSUs) are minimized.Finally, we propose a trust model to minimize the validators without compromising the decentralization and fairness of block-creation. This trust model leverages the geographical distance and the RSUs trust to dynamically form a group of validators for each block in the blockchain. We formalize and evaluate this trust model, considering various scenarios with malicious RSUs. Results show the efficiency of the proposed model to minimize the validators group while isolating malicious RSUs

Located in the city center of Kütahya, the citadel is situated on a hill overlooking the city. Taking into consideration the wall construction technique, it is thought that the present city walls and the bastions of the citadel, in particular, have been constructed during the Byzantine Period. Kütahya Citadel, known to have been inhabited during the Roman, Byzantine, Seljuk and Ottoman periods, is formed by three sections as Upper Citadel, Inner Citadel and Lower Citadel. Drawn up in 2020 with the authorization of the Kütahya Cultural Heritage Preservation Board, a recovery excavation has been performed within the scope of the “Kütahya Castle Lighting Project”. In the castle, canals have been opened around the restaurant and cafeteria, which have been built unauthorizedly within various periods since the seventies, and electrical cables and electricity supply panels have been placed. Both the cable ducts and the apparatus required for the lighting have been laid without inflicting any damage to the area, and the processes have been designed to be recyclable. Regular excavations have been initiated in the 2021 excavation season, and excavations have been conducted in ZZ-21, AB-21 and ZZ-22 grids in the Upper Citadel. Leveling works have been performed in the 10x10 trenches determined in the inner part of the 28th and 29th bastions. Alternative walls in brick and coarse stone order as well as coarse stone wall systems have been identified. Ceramics are amongst the first small finds unearthed within the two excavation seasons. Glazed and unglazed ceramic finds from the Roman, Byzantine, (Beylik) Principalities and Ottoman periods generally consist of plates, bowls, jugs, jars, cooking pots and bowls. Two silver coins minted in Constantinople (Istanbul) and Egypt during the Ottoman Period are also amongst the substantial finds recovered. Apart from coins, various metal objects and glassware finds appear as other artifacts unearthed. For more detailed information, please refer to the Extended Abstract at the end of the text