45 (665) Ziyād, whom in the preceding year the Great Caliph Mo`awiya had officially recognised as his brother, was made governor of Basra and “the East.” Al-Hakam ibn `Āmir al-Ghifārī was sent in A.H. 47 (667) on an expedition into Khorāsān. He occupied Tokhāristān and the country south and south-east of Balkh as far as the Hindu Kush, and was, moreover, the first Arabian general to cross the Oxus.[84] Al-Hakam died at Merv in A.H. 50 (670), on his return from an expedition against the people of Mount Ashall.[85] In the following year Rabī` ibn Ziyād[86] el-Hārithī was sent to Khorāsān to succeed him.[87] About this date many Arabs migrated with their families to Khorāsān and settled there.[88] Rabī`’s first care was the reduction of Balkh, which had been the scene of a revolt, and this he effected without resorting to force. He also engaged the Turks in Kūhistān, and put them to rout. Among the fugitives was Nīzak Tarkhūn,[89] who perished later at the hands of Kutayba ibn Muslim. Rabī` also crossed the Oxus, but made no conquests on the farther side.[90] His death, and that of his master Ziyād, took place in A.H. 53 (673). He named his son `Abdullah as his successor, but the latter died two months later, and was succeeded by Khulayd ibn `Abdullah el-Hanafī. On the death of Ziyād the Caliph gave the governments of Kūfa, Basra, and Khorāsān to his own son `Ubaydullah, while he appointed Ziyād’s son `Ubaydullah, in supersession of Khulayd, as his lieutenant in Khorāsān. `Ubaydullah ibn Ziyād collected an army in Irāk, entered Khorāsān and, crossing the Oxus, penetrated into the mountains of Bokhārā,[91] and conquered Rāmtīna and half of Baykand. The Turks of Bokhārā were at that time governed by a princess named Khātūn, who acted as regent during the minority of her son Tughshāda. On the approach of the Arabs with an overwhelming force, Khātūn fled to Samarkand. According to Tabari,[92] so great was her haste that one of her shoes was left behind. It fell into the hands of the Arabs, and was valued by them at 200,000 direms.[93]