Complex sentence: In the same year, he was a participant in the synod that accepted the resignation of Dositheus, the Patriarch of Constantinople, and is recorded in the acts as the senior-most of the imperial relatives.
Split into simpler sentences: In the same year, he was a participant in the synod that accepted the resignation of Dositheus, the Patriarch of Constantinople. He is recorded in the synodal acts as the senior-most of the imperial relatives.