The capture of Adrianople opened the path to Constantinople for Theodore. In order to secure his northern flank, he concluded an alliance with John Asen, sealed by the (second) marriage of his brother Manuel to Maria, an illegitimate daughter of Asen. At the same time, the Latins turned to Nicaea and concluded a peace treaty in exchange for further territorial concessions. This pact too was sealed by a marriage, of Theodore Laskaris' daughter Eudokia to the Latin baron Anseau de Cayeux. In the same summer of 1225, Theodore led his army to the environs of Constantinople, reaching the towns of Bizye and Vrysis. Anseau de Cayeux, leading the Latin army, was heavily wounded in the clashes, but Constantinople itself was not attacked. Not only was Theodore unprepared for a siege against the mighty Theodosian Walls, but news of William of Montferrat's landing at Thessaly forced him to break off operations and return west.