On the death of his father, Alexius I, the founder of the Imperial Comneni dynasty, John Comnenus II ascended the throne of the Byzantine Empire and ruled for 25 years - from 1118-1143. He was born during his father's reign, that is, after Alexius had actually ascended the throne, and hence held the title "porphyrogennitos" - "born into the purple". This word in Greek can be seen running vertically down to the right of John's figure on the mosaic. Similarly, his empress's name "Eirene" can be seen across the top of her head as can be the title "Augusta", just to the right of her head. This mosaic graces one of the walls of the south gallery in the Hagia Sophia. John was detested by his sister Anna Comnena, Alexius' biographer, for having deprived her, through their father's direct choice and decision, of the opportunity to rule. Perhaps posterity may be grateful for that fact. Had she ruled she may not have retired to a monastery and not had the time or inclination to write her biography of Alexius' life - "The Alexiad" - and we would have lost one of our major and most detailed sources of events and descriptions of court-life, during the reign of Alexius and afterwards, and also of events leading up to the First Crusades, as seen from the perspective of the East.
