He was succeeded by Peter of Courtenay, who was invited by the barons to occupy the throne in the absence of male heirs of Baldwin and his brother Henry. Peter left France with 140 knights and 5,500 men at arms, whom he had obtained with the aid of his royal kinsman, Philip Augustus. The reports of the rich plunder which had been obtained in the capture of the city had already induced many French knights to leave their native lands to take service in the empire, but the detachment with which Peter crossed the Alps was the largest which had left the West for such purpose. The Venetians bargained to transport them across the Adriatic on condition that they would assist in recovering Durazzo from Theodore, the Greek despot of Epirus. After a useless assault on that city, Peter started with his followers on a journey across the peninsula to Salonica. He and his host were soon lost amid the mountains of Epirus. Their provisions were exhausted. They found the passes fortified, and their only chance of life was to surrender to Theodore, who had held the country in defiance of the regent who was governing in the name of the son of Boniface. Peter was detained in captivity, and his death is as mysterious as that of the first Latin emperor. He probably perished in prison in 1218. [Sidenote: Robert, 1219–1228.] Peter’s successor, Robert of Courtenay, succeeded in finding his way to Constantinople, though not across Macedonia, accompanied by a number of troops furnished at the request of Pope Honorius the Third. His reign was a series of disasters. He made a treaty of peace with Theodore of Nicaea in order that he might devote all his attention to the defeat of the other Theodore, the despot of Epirus. The latter had been denounced by the pope for his detention of Peter and of the legate who accompanied him. Honorius indeed had invited the princes of the West to undertake a crusade for their deliverance. When, however, the legate was released, Peter seems to have been forgotten. The despot Theodore made a well-concerted attack upon Salonica, captured it, and was proclaimed emperor in 1222. Robert led all his forces against this new claimant for the imperial title and was badly beaten. Theodore pushed on to Adrianople and hoisted his standard on the walls of that city almost without opposition. There were thus in 1222 four persons claiming to be emperors, and occupying separate portions of what had been twenty years earlier the Roman Empire in the East. These were Robert at Constantinople, Theodore at Nicaea, another Theodore at Salonica, and Alexis at Trebizond. [Sidenote: Nicaea, success of John Ducas Vataces, 1222–1254.]