Harun was the de facto ruler (later Shah) of Khwarazm from 1032 to 1035. He was the son of Altun Tash

Altun Tash

Altun Tash was Khwarazm-Shah from 1017 until his death.Altun Tash was originally a slave commander serving the Ghaznavid Sebük Tigin. In 1008 he played a leading role in a battle against the Karakhanids at Sharkhiyan near Balkh, in which the Ghaznavids were victorious...

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Following his father's death in 1032, Harun was effectively made governor of Khwarazm by the Ghaznavid sultan Mas'ud

Mas'ud I of Ghazni

Mas'ud I seized the throne of the Ghaznavid Empire upon the death of his father Mahmud from his younger twin Mohammad who had been nominated as the heir upon the death of their father Mahmud of Ghazni. His twin was blinded and imprisoned...

. The title of Khwarazm-Shah was not given to him, but to Mas'ud's son Sa'id; Mas'ud had been distrustful of Altun Tash and probably wanted to avoid giving his son too much power. In 1034, however, Harun revolted against Mas'ud, assuming the title of Khwarazm-Shah, and turned to the Ghaznavids' enemies, the Karakhanids of Samarkand

Samarkand

Although a Persian-speaking region, it was not united politically with Iran most of the times between the disintegration of the Seleucid Empire and the Arab conquest . In the 6th century it was within the domain of the Turkic kingdom of the Göktürks.At the start of the 8th century Samarkand came...

 and the Seljuks, for support. Mas'ud managed to put an end to this revolt by gaining the support of Harun's guards, who assassinated him. Khwarazm then fell to Harun's brother Ismail Khandan

Ismail Khandan

Isma'il Khandan was the ruler of Khwarazm, an ancient state along the previous Aral Sea, from 1035 to 1041 AD. He was the son of Altun Tash.In 1035 Isma'il's brother Harun was assassinated by his guards at the instigation of the Ghaznavid sultan Mas'ud I of Ghazni...

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