(Ἑνρῖκος), HENRY, a Greek emperor (A. D. 1206-1216), the second son of Baldwin VIII., count of Flanders and Hainaût, was born about 1176, and succeeded his elder brother Baldwin on the throne of Constantinople in 1206. [BALDUINUS I.] Henry was one of the leading chiefs in the great expedition of the Latin barons against Constantinople, in 1204, and in the division of the empire was rewarded with territories in Asia, which, however, he had first to wrest from Theodore Lascaris and the other leaders of the rebellious Greeks. He defeated Lascaris in a bloody battle near Adramyttium in Mysia, in 1205, and the conquest of Bithynia was the fruit of his victory. The emperor's campaign against the Bulgarians obliged him to repair to the other side of the Bosporus, and he left Asia at the head of 20.000 Armenian mercenaries, with whom he marched upon Adrianople. Before he had reached that town, he was informed that Baldwin, without waiting for the arrival of his brother, had imprudently engaged a pitched battle with the Bulgarian king, Joannicus or Calo-Joannes, that the imperial troops had suffered a severe defeat, and that nobody knew what had become of the emperor (15th of April, 1205). In this emergency, Henry left his army, and hastening alone to the field of battle near Adrianople, arrived in time to save the imperial army from utter destruction. The fate of Baldwin being entirely unknown, Henry was chosen regent, and he conducted his forces back to Constantinople. The Bulgarian king followed in his steps, burnt Philippopolis, and ravaged all Thrace in a most savage manner. He reckoned upon the assistance of the discontented Greeks, and, had they joined him, the fate of the new Latin empire of Constantinople would have been sealed; but his unheard-of cruelties showed the Greeks that among their foreign masters the Bulgarian was the worst; and the inhabitants of Adrianople, after having defended their town against Henry as an usurper and tyrant, now opened their gates, and received him within their walls with acclamations of joy. This was in 1206. It was then known that the emperor Baldwin was a prisoner of the king of Bulgaria, and in the summer of 1206 the news came of his melancholy death. Henry, known as a skilful general, endeared to most of the Latin barons for having saved them after the defeat of Adrianople, and moreover next of kin to his brother, was unanimously chosen emperor, and crowned at Constantinople on the 20th of August, 1206. At the same time Theodore Lascaris was recognised by a large number of towns and villages as lawful emperor, and took up his residence at Nicaea. From that time down to 1261, there was a Latin-Byzantine and a Greek-Byzantine empire, to which we must add a third, the Greek empire of the Comneni at Trebizond. An alliance between the king of Bulgaria and Theodore Lascaris placed Henry in great danger. He kept the field in Thrace and Asia with great bravery, and found additional strength in an alliance with the Marquis of Montferrat, lord or king of Thessalonica, whose daughter Agnes he married; but he lost her soon afterwards. In 1207 Joannicus died, and Henry concluded a political marriage with his daughter, which led to a lasting state of peace with Phrorilas, the brother and successor of Joannicus. He also made a truce with Theodore Lascaris, who was hard pressed by David, the gallant brother and general of Alexis I., the new emperor of Trebizond. In 1214, Theodore Lascaris formed a most advantageous peace with Alexis, and now suddenly invaded Bithynia, surprised the troops of Henry which were stationed there, and conquered them in a pitched battle. To avenge this defeat, Henry crossed the Bosporus with a chosen army, and laid siege to Pemanene. The town surrendered after an obstinate resistance, which so roused the resentment of Henry, that he ordered the three principal officers of the garrison to be put to death, viz. Dermocaitus, Andronicus Palaeologus, the brother-in-law of Theodore Lascaris, and a brother of Theodore Lascaris, whose name is not mentioned, but who was undoubtedly the brave Constantine Lascaris, who defended Constantinople with so much gallantry against the Latins in 1204. The issue of the campaign, however, was not very favourable to Henry, for he obtained peace only on condition of ceding to his rival all the territories situate east of a line drawn from Sardis to Nicaea, and to leave Theodore Lascaris in possession of those which he had conquered west of that line in Bithynia previous to the truce mentioned above. In 1215 the fourth Lateran council was assembled by pope Innocent III., and a kind of mock union was formed between the Roman and Greek churches within the narrow dominions of Henry. Gervasius was made patriarch of Constantinople, and recognised by both Henry and the pope, who besides declared Constantinople the first see of Christendom after Rome. In the following year (1216), Henry set out to wage war with his former friend Theodore, despot of Epeirus and Aetolia, but died suddenly, before any hostilities of consequence had taken place. It is said that he died by poison, and both the Greeks and the Latins are charged with the murder; but the fact is doubtful. Henry left no male issue, and was succeeded by Peter of Courtenay.

In spite of the perpetual wars into which he was driven by circumstances, and which he carried on with insufficient means, Henry found time to ameliorate the condition of his subjects by several wise laws and a careful and impartial administration. Towards the Greeks he showed great impartiality, admitting them to the highest offices of the state, and never giving any preference to his own countrymen or other foreigners; and there are many passages in the Greek writers which prove that the Greeks really loved him. To make a nation forget a foreign yoke is, however, no easy task, and no ruler has ever succeeded in it but by displaying in equal proportions valour, energy, prudence, wisdom, and humanity. For these qualities great praise has been bestowed upon Henry, and he well deserved it. (Gregoras, lib. i. ii.; Nicetas, p. 410, &c., ed. Paris; Acropolita, 100.6, &c.; Villehardouin, De la Conqueste de Constantinoble, ed. Paulin Paris, Paris, 1838.)