His foreign policy was as perfidious as his domestic. He attacked Shahrisabz, a little state enclosed in his dominions, which had, like Holland, preserved its independence by the bravery of its people and their ability to lay the environs of their capital under water at an invader’s approach.[499] He was baffled, and Shahrisabz continued to be a thorn in his side during his long reign,--albeit that he endeavoured to gain a footing there by espousing the ruler’s sister. With Kokand he was more successful. That state was governed by Khān Mohammad `Alī, a prince descended in the female line from the great Baber, emperor of Hindustān, who had won glory by successes against the Chinese on his western frontier.[500] Thus he incurred Nasrullah’s jealousy, and his ruin was determined on. It was compassed by the aid of a Persian soldier of fortune named `Abd us-Samad Khān, who had fled his country after attempting to assassinate his master.[501] He knew how to cast and work cannon--engines of war which exercise an overwhelming influence on the Oriental mind; and commended himself to Nasrullah by military knowledge and an eagerness to pander to his worst vices. He became his _âme damnée_, even as the infamous “Azimulla” prompted every atrocity committed by Nana Sahib during the Indian Mutiny. The excuse for aggression was afforded by the frontier fortress of Pishagar, which Nasrullah declared had been erected by the Kokandis on his territory. Its destruction was peremptorily demanded; and, on Mohammad `Alī’s refusal to comply, it was attacked by a strong force, accompanied by a breaching battery under `Abd us-Samad’s command.[502] The mud walls of Pishagar were unable to resist the iron shower, and its surrender was followed in the succeeding year by that of Ura Teppe and of Khojend. The Khān of Kokand, seeing that the capital was in peril, sued for peace, and, by the treaty of Kohna Bādām, ceded Khojend and recognised the Bokhāran Amīr as his suzerain. With the cunning which in the East passes for the highest manifestation of diplomacy, Nasrullah placed the newly conquered territory under the governorship of Sultan Mahmūd, a brother of the Khān of Kokand and a pretender to his throne. But hardly were these arrangements completed ere Mahmūd and his brother came to terms, and both Khojend and Ura Teppe were temporarily lost to Bokhārā. The wrath of the Amīr was unbounded. In April 1842 he took the field against Kokand with a host of 30,000 horsemen and regulars,[503] and 10,000 Turkoman mercenaries. He reached Khojend by forced marches, and captured that city without firing a shot, though it was defended by a garrison 15,000 strong.[504] Thence he moved rapidly on the capital and drove Mohammad `Alī to seek refuge in Marghilān. Here he was taken prisoner, dragged back to Kokand, and slaughtered with the greater part of his relatives.[505]