Diplomacy gained for Bokhārā what arms could never have accomplished. Khātūn saved the evacuation of her capital by entering into a treaty by which she bound herself to pay a yearly tribute.[94] `Ubaydullah withdrew to Merv laden with booty, and on his return to Irāk was appointed by the Caliph Mo`awiya, governor of Basra. In A.H. 56 (676) Sa`īd ibn `Othman, who had superseded him in Khorāsān, determined to complete the conquest of Bokhārā, in spite of the treaty concluded by his predecessor. The Queen-Regent Khātūn was powerless to resist the invasion, for she had reason to doubt the loyalty of her troops, and her resources had been well-nigh exhausted in her struggle with `Ubaydullah. She therefore came to terms with Sa`īd by the surrender of the last shreds of her sovereignty in Bokhārā. But Samarkand, the wealthiest of its strongholds, was still unmastered. Sa`īd ibn `Othman embarked on a campaign for its reduction, carrying with him eighty Bokhārān nobles as hostages for their queen’s good behaviour. After several successful engagements with the Turks he stormed Samarkand[95] and carried off 30,000 prisoners, with much booty.[96] When Sa`īd passed through Bokhārā on his return to Khorāsān the queen demanded back the eighty hostages, but he replied that he did not yet feel sure of her good faith, and that he would not part with the Bokhārāns until he had crossed the Amū Daryā. At this stage of his march the queen sent messengers to repeat her demand, but she was informed by Sa`īd that the hostages should be sent back from Merv. Thus he continued to elude compliance, and finally dragged his wretched captives to Medīna. Here they were stripped of the attire proper to their rank and reduced to a condition of slavery. Preferring death to an ignominious existence, the desperadoes broke into Sa`īd’s palace, and, closing fast the doors, slew him and afterwards themselves. This tragedy occurred in A.H. 61 (680), under the Caliphate of Yezīd ibn Merwān, who had succeeded his father Mo`awiya in the previous year.