JOHN OF BRIENNE (c. 1148-1237)  , king of Jerusalem and Latin emperor of Constantinople, was a man of sixty years of age before he began to play any considerable part in history . Destined originally for the Church, he had preferred to become a knight, and in forty years of tournaments and fights he had won himself a considerable reputation, when in 1208 envoys came from the Holy Land to ask Philip Augustus, king of France, to select one of his barons as husband to the heiress, and ruler of the kingdom, of Jerusalem . Philip selected John of Brienne, and promised to support him in his new dignity . In 1210 John married the heiress Mary (daughter of Isabella and Conrad of Montferrat), assuming the title of king in right of his wife . In 1211, after some desultory operations, lie concluded a six years' truce with Malik-el-Adil; in 1212 he lost his wife, who left him a daughter, Isabella; soon afterwards he married an Armenian princess . In the fifth crusade (1218–1221) he was a prominent figure . The legate Pelagius, however, claimed the command; and insisting on the advance from Damietta, in spite of the warnings of King John, he refused to accept the favourable terms of the sultan, as the king advised, until it was too late . After the failure of the crusade, King John came to the West to obtain help for his kingdom . In 1223 he met Honorius III. and the emperor Frederick II. at Ferentino, where, in order that he might be connected more closely with the Holy Land, Frederick was betrothed to John's daughter Isabella, now heiress of the kingdom . After the meeting at Ferentino, John went to France and England, finding little consolation; and thence he travelled to Compostella, where he married a new wife, Berengaria of Castile . After a visit to Germany he returned to Rome (1225) . Here he received a demand from Frederick II .

(who had now married Isabella) that he should abandon his title and dignity of king, which—so Frederick claimed—had passed to himself along with the heiress of the kingdom . John was now a septuagenarian " king in

exile," but he was still vigorous enough to revenge himself on Frederick, by commanding the papal troops which attacked southern Italy during the emperor's absence on the sixth crusade (1228-1229) . In 1229 John, now eighty years of age, was invited by the barons of the Latin empire of Constantinople to become emperor, on condition that Baldwin of Courtenay should marry his second daughter and succeed him . For nine years he ruled in Constantinople, and in 1235, with a few troops, he repelled a great siege of the city by Vataces of Nicaea and Azen of Bulgaria . After this last feat of arms, which has perhaps been exaggerated by the Latin chroniclers, who compare him to Hector and the Maccabees, John died in the habit of a Franciscan friar . An aged paladin, somewhat uxorious and always penniless, he was a typical knight errant, whose wanderings led him all over Europe, and planted him successively on the thrones of Jerusalem and Constantinople . The story of John's career must be sought partly in histories of the kingdom of Jerusalem and of the Latin Empire of the East, partly in monographs . Among these, of which R . Rohricht gives a list (Geschichte des Konigreichs Jerusalem, p . 699, n . 3), see especially that of E. de Montcarmet, Un chevalier du temps passe (Limoges, 1876 and 1881) .