Before long he had so gained the caliph's confidence that Mamun gave him his freedom and the command of the guard, at the same time appointing him Emir es-sitri, prince of the veil or curtain. This post, which was a mark of the greatest esteem, comprised the charge of the personal safety of the sovereign, by continually keeping watch without the curtain or rich drapery which hung before the private apartments, and admitting no one without a special order. Tulun spent twenty years at the court of el-Mamun and of his successor, Mutasim, and became the father of several children, one of which, Ahmed ibn Tulun,* known later as Abu l'Abbas, was the founder of the Tulunide dynasty in Egypt and Syria. * Ahmed ibn Tulun was, according to some historians, born at Baghdad in the year 220 of the Hegira, in the third year of the reign of el-Mutasim b' Illah. Others claim Samarrah as his birthplace. His mother, a young Turkish slave, was named Kassimeh, or some say, Hachimeh. Some historians have denied that Ahmed was the son of Tulun, one of them, Suyuti, in a manuscript belonging to Marcel, quotes Abu Asakar in confirmation of this assertion, who pretends he was told by an old Egyptian that Ahmed was the son of a Turk named Mahdi and of Kassimeh, the slave of Tulun. Suyuti adds that Tulun adopted the child on account of his good qualities, but this statement is unsupported and seems contradicted by subsequent events. Before Ahmed ibn Tulun had reached an age to take part in political affairs, two caliphs succeeded Mutasim b'lllah. The first was his son Harun abu Jafar, who, upon his accession, assumed the surname el-Wathik b'lllah (trusting in God). Wathik carried on the traditional policy of continually changing the governors of the provinces, and, dying in the year 847, was succeeded by his half-brother Mutawakkil. In the following year the new caliph confided the government of Egypt to Anbasa, but dismissed him a few months later in favour of his own son el-Muntasir ibn el-Mutawakkil, whom two years afterwards the caliph named as his successor to the throne. El-Muntasir was to be immediately succeeded by his two younger brothers, el-Mutazz b'lllah and el-Mujib b'lllah. Mutawakkil then proceeded to divide his kingdom, giving Africa and all his Eastern possessions, from the frontier of Egypt to the eastern boundary of his states, to his eldest son. His second son, el-Mutazz, received Khorassan, Tabaristan, Persia, Armenia, and Aderbaijan as his portion, and to el-Mujib, his third son, he gave Damascus, Hemessa, the basin of the Jordan, and Palestine.