Michael Glykas or Glycas () was a 12th-century Byzantine historian, theologian, mathematician, astronomer and poet. He was probably from Corfu and lived in Constantinople. He was a critic of Manuel I Komnenos, and was imprisoned and blinded due to his participation in a conspiracy against the emperor. He is also identified by modern scholarship with Michael Sikidites (Μιχαὴλ Σικιδίτης), who was condemned as a heresiarch in 1200. Life Glykas was born sometime in the first third of the 12th century, possibly . His probable birthplace was Corfu. He served as imperial secretary (grammatikos) under Emperor Manuel I Komnenos (), before being involved in a conspiracy against the emperor and being blinded. The blinding was probably partial or slight, since he continued his literary activity. The exact nature of this conspiracy is unknown, but Otto Kresten suggested a connection with the alleged conspiracy that led to the downfall of Manuel's chief minister Theodore Styppeiotes in 1158/9. He remained imprisoned until at least 1164, and his subsequent fate is unknown. Modern scholars commonly support his identity with a certain Michael Sikidites, charged with heresy and magic in . According to Niketas Choniates, this Sikidites "was enrolled among the imperial secretaries" of Manuel I, was known of performing magic spells, conjuring serpents and demons. He preached a doctrine according to which the sacraments of the Eucharist were mortal and corruptible, as Christ's own body was. Furthermore, Sikidites and his followers considered a bodily resurrection impossible, and thought that the dead would be resurrected as ghostly spirits only. The doctrine appears to have enjoyed some support in leading circles, notably of the Patriarchs of Constantinople George II Xiphilinos and John X Kamateros, but also aroused passionate opposition; in a synod in 1200, Sikidites was censured and his teachings declared heretical. Works His first known work were his Verses from Prison, a poem of 581 lines in political verse, written during his imprisonment. It contains many elements of the vernacular Greek language of his time (an early form of Modern Greek), in contrast to the highly stylized and archaic Attic Greek favoured by Byzantine intellectuals. In 1164/65, he composed an encomium celebrating Emperor Manuel's Hungarian campaign. He also wrote a mathematical treatise on the distinction between astronomy and astrology, where he severely criticised Manuel I for his fondness for the latter; in the same vein, Glykas strongly rejected the concept of inevitable fate (ananke) as