Michael was a well-educated man and a member of the literary circle around Eustathius of Thessalonica.
In the ecclesiastic hierarchy, he had reached the post of megas sakellarios at the time of the sack of Constantinople by the Fourth Crusade in 1204.
[3] In 1208 he was made patriarch by Theodore I Laskaris, in succession of John X of Constantinople who had died in 1206.
Laskaris had established a Byzantine Greek successor state in Asia, the Empire of Nicaea, and had tried to persuade John X to join him, but he had refused because of old age and died shortly after.
He also took the highly unusual move, contrary to both Byzantine tradition and Orthodox doctrine, of promising remission of sins for Laskaris' soldiers who fell in battle.