From the very beginning the Latin settlers had to contend against dissension within and invasion from without. Boniface of Thessalonica married the widow of Isaac Angelus, Margaret of Hungary (called by the Greeks Irene), and posed as an independent prince and the protector of the Greek population. He refused homage to the Emperor, and war broke out between the Flemings of Constantinople and the Lombards of Thessalonica. No sooner were his pretensions rudely shattered than the Emperor was called away to meet the danger of Bulgarian invasion. Johanitsa, the tsar of the Bulgarians, turned his arms against the Crusaders, and invaded Thrace. In April 1205, a decisive battle was fought at Adrianople, when the simulated flight of the wild Bulgar hordes drew the chivalry of the West to break up their solid ranks. [Sidenote: Baldwin I., 1204–1205.] Thereupon the Bulgarians rallied, and took advantage of the enemy’s disorder to inflict on them a complete defeat. Louis of Blois was among the slain. Baldwin was taken prisoner and murdered. The Marshal of Champagne, and Henry of Flanders, Baldwin’s brother, almost alone survived of the Latin chieftains. [Sidenote: Henry, 1206–1216.] Henry of Flanders had already made some progress in the conquest of Greek Asia, when the news of the Bulgarian invasion called him to defend his brother’s throne. He was now recognised as Emperor. He was politic as well as brave, and the Greeks themselves admitted that he ‘treated the Romans as if they were his own people.’ But he could neither conquer Asia, defeat the Bulgarians, nor even permanently conciliate his Greek subjects; though his zeal for shielding them from Catholic persecution drew upon him the thunders of the Vatican. He made a treaty with Theodore Lascaris, which gave him at least a little corner of Asia. He was the strongest of the Latin Emperors. But he profited by the even greater weakness of the kingdom of Thessalonica. In 1207, Boniface of Montferrat perished, like Baldwin, at the hands of the Bulgarians. The Despot of Epirus took advantage of the minority of his infant son, Demetrius, to extend his conquests. The Frankish lords of the kingdom called in the Emperor Henry, who found some consolation for his disappointments in the North, when he gave the law to the Peloponnesus and the islands in a great Diet held in 1210, compelled the regent of the young king to do him homage, and received the submission even of the Venetian lords of the Archipelago, conferring on the great house of Sanudo the Duchy of the Archipelago or the Cyclades. Even the Despot of Epirus formally acknowledged his sovereignty. Henry died in 1216, and with him perished the best hopes of the Latins in Greece. [Sidenote: Peter of Courtenay, 1216–1219.]