Isthmus of Corinth. His attack opened the peninsula to invasion, though Murad died before he could exploit this. His successor Mehmed II "the Conqueror" captured the Byzantine capital Constantinople in 1453. The despots Demetrios and Thomas Palaiologos, brothers of the last emperor, failed to send him any aid, as Morea was recovering from a recent Ottoman attack. Their rule was unpopular, however, resulting in an Albanian–Greek revolt against them, during which they invited Ottoman troops to help them put down the revolt. At this time, a number of influential Greek archons made peace with Mehmed. After more years of incompetent rule by the despots, their failure to pay their annual tribute to the Sultan, and finally their own revolt against Ottoman rule, Mehmed came into the Morea in May 1460. Demetrios ended up a prisoner of the Ottomans and his younger brother Thomas fled. By the end of the summer, the Ottomans had achieved the submission of virtually all cities possessed by the Greeks. A few holdouts remained for a time. The rocky peninsula of Monemvasia refused to surrender, and it was first ruled for a brief time by a Catalan corsair. When the population drove him out, they obtained the consent of Thomas to submit to the Pope's protection before the end of 1460. The Mani Peninsula at the south end of the Morea resisted under a loose coalition of the local clans, and that area then came under Venice's rule. The last holdout was Salmeniko, in the Morea's northwest. Graitzas Palaiologos was the military commander there, stationed at Salmeniko Castle (also known as Castle Orgia). While the town eventually surrendered, Graitzas and his garrison and some town residents held out in the castle until July 1461, when they escaped and reached Venetian territory. Thus ended the last of the Byzantine Empire proper. After 1461, the only non-Ottoman territories were possessed by Venice: the port cities of Modon and Koroni at the southern end of the Morea, the Argolid with Argos, and the port of Nafplion. Monemvasia subsequently surrendered itself to Venice at the beginning of the 1463–1479 Ottoman–Venetian War. Byzantine despots of the Morea House of Kantakouzenos (1349–1383) House of Palaiologos (1383–1460) Following the Ottoman conquest of the Morea, the title continued to be used by Thomas Palaiologos and his son Andreas in exile; After the death of Andreas in 1502, the title was claimed by the Albanian