At the very beginning of his reign, the emperor Leo V faced a new Bulgarian offensive that reached the walls of Constantinople and ravaged large sections of Thrace. This came to an end with the death of Krum on April 13, 814, and the internal power struggles that followed. However, as the previous 30 years since the approval of icon-veneration at the Synod of 787 had represented for the Byzantines a string of military catastrophes, Leo resolved to reach back to the policies of the more successful Isaurian dynasty. He renamed his son Constantine, thus drawing a parallel to Leo III (r. 717–741) and Constantine V, and beginning in 814 began to discuss with various clerics and senators the possibility of reviving the iconoclastic policy of the Isaurians. This movement met with strong opposition from the Patriarch Nikephoros, who himself gathered a group of bishops and abbots about him and swore them to uphold the veneration of images. The dispute came to a head in a debate between the two parties before the emperor in the Great Palace on Christmas 814, at which Theodore and his brother Joseph were present and took the side of the iconophiles.