Recalled by Michael I Rangabe in 811, Leo became governor of the Anatolic theme and conducted himself well in a war against the Arabs in 812, defeating the forces of the Cilician "thughur" under Thabit ibn Nasr. Leo survived the Battle of Versinikia in 813 by abandoning the battlefield, but nevertheless took advantage of this defeat to force the abdication of Michael I in his favor on 11 July 813. In a diplomatic move, he wrote a letter to Patriarch Nikephoros in order to reassure him of his orthodoxy (Nikephoros being obviously afraid of a possible iconoclast revival). One month later, during his entrance to the Palace quarter, he kneeled before the icon of Christ at the Chalke Gate. A further step in preventing future usurpations was the castration of Michael's sons.