to seize the crown for himself, leaving his retirement in 1182 and marching to Constantinople with an army that (according to non-Byzantine sources) included Muslim contingents. Alexios attempted to negotiate, and sent George Xiphilinos (a future patriarch) to Andronikos' camp, offering a pardon and high office. In the event, Xiphilinos betrayed the prōtosebastos, and Andronikos rejected the offer, insisting instead that the prōtosebastos retire and be held accountable for his administration, and the empress-dowager be confined to a convent. The defection of the commander of the Byzantine navy, megas doux Andronikos Kontostephanos, and the defeat and defection of his cousin general Andronikos Angelos, played a key role in allowing the rebellious forces to enter Constantinople. The arrival of Andronikos Komnenos was soon followed by a massacre of the city's Latin inhabitants, who virtually controlled its economy, resulting in the deaths of thousands of Westerners. He was believed to have arranged the poisoning of Alexios II's elder sister Maria the Porphyrogenita and her husband Renier of Montferrat, although Maria herself had encouraged him to intervene; the poisoner was said to be the eunuch Pterygeonites. Soon afterwards Andronikos had the Empress Maria imprisoned and then killed – forcing a signature from the child Emperor Alexios to put his mother to death – by Pterygeonites and the hetaireiarches Constantine Tripsychos. Alexios II was compelled to acknowledge Andronikos as colleague in the empire in front of the crowd on the terrace of the Church of Christ of the Chalkè and was then quickly put to death in turn; the killing was carried out by Tripsychos, Theodore Dadibrenos, and Stephen Hagiochristophorites. In 1183, sixty-five-year old Andronikos married twelve-year-old Agnes of France, daughter of King Louis VII of France and his third wife Adèle of Champagne – Agnes had been betrothed to Alexios II. By November 1183, Andronikos had associated his younger legitimate son John Komnenos on the throne. In 1184, a Venetian embassy visited Constantinople, and an agreement was reached that compensation of 1,500 gold pieces would be paid for the losses incurred in 1171. The reign of Andronikos was characterized by his harsh measures. He resolved to suppress many abuses but above all things to check feudalism and limit the power of the nobles, who were rivals for his throne. He attempted to reform the decaying political system by forbidding the sale of offices, punishing corrupt officials (often brutally) but above all, he moved