The Byzantine Empire
Wars Among Emperors
1205: Renier de Trit took Philippopolis and became duke there. Bonfiace of Montferrat took Thebes and Athens and Corinth. Geoffrey of Villehardouin (nephew of the historian) landed at Methone and began the conquest of the Morea. Marco Sanudo, nephew of the doge, captured Naxos and took many more of the Cyclades in 1207. He became Duke of the Aegean Sea, or Duke of the Archipelago. Ionnitsa captured Adrianople, though, and Thrace rebelled. Baldwin laid siege to Adrianople but was captured. Henry arrived and succeeded. The Kumans left, so Ionnitsa was forced to raise the siege. He advanced on Philippopolis. Renier de Trit was in the citadel. Ionnitsa believed the Greeks betrayed him and massacred the population. Henry was crowned emperor on August 20, 1206.
1207: Henry allies with Trebizond to attack Theodore Lascaris. The Latins win Nicomedia and other towns. Lascaris allied with Ionnitsa and forced Henry to fight on two fronts. Henry won peace, but he had to give up all Latin holdings in Asia Minor save Pegae and Cyzicus. February 1207, Henry marries Agnes, daughter of Boniface of Montferrat. Summer, Boniface is killed in a skirmish with Bulgars. Ionnitsa died at this time, of a hemorrhage of the lungs. Bulgaria dissolved in civil war between three claimants.
August 1, 1208 Henry defeated a much larger Bulgarian army at Philippopolis. Henry begins his quarrel with the Lombards over Thessalonica and other issues. The Lombards, led by the regent for Boniface's infant son, Biandrate, still believed Boniface should have been emperor. They had another candidate in mind, and they used Thessalonica as a base for their defiance. Henry was able to win a small victory in the winter, but Biandrate continued to plot against him. In the spring of 1209, Henry was able to win more victories. Thessaly submitted to him, and the Morea as well; Villehardouin became the seneschal of the Empire. Henry captured Thebes and was welcomed into Athens. After landing in Euboea and winning over the local magnates, Henry at last received Biandrate's submission as well. This ended the Lombard revolt.
Because of Henry's great successes in Greece, the Despot of Epirus, Michael, made a treaty. But he violated it in 1210. War between Constantinople and Epirus continued until 1212, ending in victory for Henry, though Michael continued to reign in Epirus.