He soon became a considerable person; married Isaac's sister, and defeated and killed a usurper; but he was repaid by ingratitude and suspicion, and fled from Constantinople to Palestine in 1187.
David's friendly relations with the Philistines find a parallel in Isaac's covenant with Abimelech.
In the same year, however, Isaac was dethroned by his brother, Alexius III.; but Henry married Isaac's daughter Irene to his brother, Philip of Swabia, and thus attempted to give the Hohenstaufen a new title and a valid claim against the usurper Alexius.
Further incidents in Isaac's life at Gerar are narrated in Gen.
Among Sir Isaac's writings is Rex platonicus, a description of the entertainment of James I.
For attempts to find a mythological interpretation of Isaac's life, see Goldziher, Mythology of the Hebrews; Winckler, Gesch.
Isaac's only military expedition was against the Hungarians and Petchenegs, who began to ravage the northern frontiers in 1059.
Isaac's great aim was to restore the former strict organization of the government, and his reforms, though unpopular with the aristocracy and the clergy, and not understood by the people, certainly contributed to stave off for a while the final ruin of the Byzantine empire.
Isaac's mention of the Huns in I.