Theodore's activities in his final years are somewhat difficult to trace. He continued to write numerous letters supporting the use of icons, and appears to have remained an important leader of the opposition to imperial iconoclasm. He was present at a meeting of "more than a hundred" iconodule clerics in 823 or 824, which ended in an argument between the Studites and the host, one Ioannikos, which may have represented a power struggle within the movement. Theodore also spoke against the second marriage of Michael II to the nun Euphrosyne, a daughter of Constantine VI, although in a very moderate fashion, and with none of the passion or effect of the Moechian controversy.