Aer: liturgical veil placed over the eucharistic elements on the altar.
Ailios Aristeides (ca. 117 or 129-189 BC): Orator belonging to the Second Sophistic movement. His ideas were different from those of Plato and he believed in the primary importance of rhetoric. Perhaps this was one of the reasons for which he was extremely popular with the Byzantines, such as Maximos Planoudes, Theodora Raoulaina, Theodore Metochites, Thomas Magistros and John Chortasmenos.
Aisle: part of the body of a church, which is defined by the interior series of its supports, pedestals or columns.
Akathistos Hymn ("not seated"): Hymn honouring the Virgin, which is sung during Lent. According to tradition, it was created in praise and thankfulness to the Virgin for her intervention in the salvation of Constantinople at the time of the Avar attack in 626. It was originally sung by a standing congregation.
Aktouarios: a title given to physicians, possibly to the head physician of the imperial court.
Akindynos Gregory (ca. 1300-1348): Anti-Palamite theologian, protege of Irene Choumnaina, who received a very good secular education. He was ordained deacon and then priest in 1344 by John XIV Kalekas. He was sent into exile following his excommunication at the Council of Blachernai and died shortly afterwards. His most famous anti-Palamite theological treatise was the Antirrhetics, containing arguments against the teaching of Palamas.
Albanians: National group of unclear origin. One theory suggests that they may have been descendants of the ancient Illyrians who survived the period of barbarian invasions and by the 11th century had settled in the region of the Arbanon valley. Later (13th-14th century) they settled in Epiros and Thessaly, while one group reached as far south as the Palaiologan Morea.
Alexios I Komnenos: Emperor of Byzantium from 1081 to 1118. Thanks to his successful foreign policy and the reforms he instituted in the administration and economy of the state he is considered to be one of the emperors whose role in the history of the empire was a decisive one.
Alexios III Angelos: Emperor of Byzantium from 1195 to 1203. After the invasion of Constantinople by the Crusaders and after having suffered various trials and tribulations, Alexios died in Nicaea in 1211/2.
Alexios Philanthropenos: Nephew of Andronikos II, whom his uncle appointed general and doux of the theme of Thrakesion in Asia Minor. He soon rebelled against the emperor, and was arrested and blinded in 1295.
Amadeo VI of Savoy ("the Green Count"): Count of Savoy (1343-1383). Leader of a Crusade in 1364 to assist the Byzantine emperor John V in his fight against the Turks, in which, in 1366-7, he scored some successes.
Anagnostes: Initially a layman and later a cleric in minor orders, whose function it was to read, from the ambo, during the Liturgy, texts from the Epistles and the Old Testament.
Andronikos II Palaiologos: Byzantine emperor (1282-1328) known for his deep piety. He restored Orthodoxy in 1282 after the failure of the Union of the Churches at Lyons in 1274. His reign ended when he abdicated in 1328 in favour of his grandson, Andronikos III, at the end of a civil war between the two. He died as monk Anthony in 1332.
Andronikos III Palaiologos: Byzantine emperor (1328-41). He assumed the imperial title after the civil war which brought him into conflict with his grandfather, Andronikos II. He endeavoured to restore the Byzantine Empire. Influenced by his wife, Anna of Savoy, he introduced Western chivalric customs into the imperial court.
Andronikos IV Palaiologos: Emperor of Byzantium (1376-79) and son of John V. Thank to the help of the Genoese of Galata and the Ottomans he remained on the Byzantine throne for three years. In 1385 he rebelled against his father and was killed in battle.
Anna of Savoy (1st half of 14th century): Empress of Byzantium and wife of Andronikos III Palaiologos. She exerted considerable influence on her husband as well as on the Byzantine court, to which she introduced Western ways and chivalric customs. After the death of her husband, she became involved, as a member of the regency of her son John V, in the civil war against Kantakouzenos.
Anna Palaiologina: Niece of the emperor Michael VIII Palaiologos (daughter of his sister Irene-Eulogia) and wife of the sovereign of Epiros, Nikephoros I.
Anthony IV: Patriarch of Constantinople (1389-90 and 1391-97).
Aplekton: tax levied for the maintenance of soldiers, probably for a short period of time.
Apocrypha: religious works, which are not accepted by the official Church. These texts constituted a source of inspiration for the Byzantine artists. A characteristic example is the Protoevangelion of James, which refers to the life of the Virgin and the childhood of Jesus.
Apokaukos Alexios: Byzantine official, one of the leaders in the rebellion of Andronikos III against his grandfather, emperor Andronikos II. After the death of Andronikos III death in 1341, he became involved, as a member of the regency, in the civil war against Kantakouzenos, by whose followers he was murdered in 1345.
Aquinas Thomas (1224-1274): Italian master of theology in the Dominican Order. The form of scholasticism he introduced, later known as Thomism, used the philosophical methods and principles of Aristotelian metaphysics. His works, translated by Demetrios Kydones and Gennadios II Scholarios, became known in Byzantium through the Dominican monks who lived in the East.
Argyropoulos John: Writer and teacher of ancient Greek philosophy in Constantinople and in Italy. He was a member of the Byzantine delegation to the Council of Ferrara-Florence and translated Greekk philosophical and theological works into Latin besides producing rhetorical and theological works of his own.
Arsenios Autoreianos-Arsenites: Patriarch of Constantinople (1254-59 and 1261-65). A supporter of the rights of the Laskarids and a defender of the observation of the rules of the Church. He was deposed by Michael VIII Palaiologos. His followers, the Arsenites, broke away from the official Church, causing what became known as the Arsenite schism, which ended in 1310 when a compromise was negotiated with the Church, during the reign of Andronikos II.
Athanasios I: Patriarch of Constantinople (1289-1293 and 1303-1309). He was involved in the Arsenite schism, he was an advocate of virtuous life and monasticism and was active in the fight against poverty in the city, for which he was canonised shortly before 1368.
Atticism: archaising and artificial form of Greek, imitating the language of the Athenian writers of the 5th-4th century BC, used in Byzantine literature.