Peter of Courtenay, Count of Auxerre, a grandson of Louis VI. of France, and the husband of Iolande, sister of Baldwin and Henry, was now chosen Emperor. He was in Europe at the time of his election, and hastened to Constantinople to take possession of the Empire. He rashly chose to disembark at Durazzo and follow the ancient Via Egnatia over the hills to Macedonia and Thrace. When amongst the mountains, his little army was overwhelmed by the Despot of Epirus, and he himself was captured, and died in captivity. His wife, who had more prudently proceeded to Constantinople by sea, now acted as regent for her young son Robert, the next Emperor. [Sidenote: Robert, 1219–1228.] The reign of Robert of Courtenay marked the rapid decline of the Eastern Empire. It witnessed the complete destruction of the Kingdom of Thessalonica. In 1223, when King Demetrius was abroad, seeking in vain Western help, Theodore Angelus took possession of his capital, and henceforth ruled without a rival from the Adriatic to the Ægean; and, like the lords of Nicæa and Trebizond, assumed the pompous style of Emperor of the Romans. [Sidenote: Fall of Thessalonica, 1223.] John Vatatzes, the successor of Theodore Lascaris at Nicæa, renewed the war with the Latins of Constantinople. It seemed almost a race between the two Theodores, as to which should first drive out the Latins. The domain of Robert was reduced to Constantinople and its suburbs. He went to implore help from the West, and died during his journey in 1228. [Sidenote: Baldwin II., 1228–1261.]