Sogdia, also known as Sogdiana, is a historical region of Central Asia located at the junction of Uzbekistan, Tajikistan, Kazakhstan, and Afghanistan. During ancient times, Sogdia bordered Bactria to the south, Khwarezm to the west, and the Tarim Basin to the northeast, and its major cities included Samarkand, Bukhara, Khojand, Panjikent, and Shahrisabz. Sogdia was home to the ancient Sogdians, who were conquered by the Achaemenid Persian emperor Cyrus the Great before being conquered from the Persians by the Macedonian king Alexander the Great in 328 BC after his capture of the Sogdian Rock. It would later fall into the hands of the Seleucids, the Greco-Bactrian Kingdom, the Kushan Empire, the White Huns, and Sassanid Persia. Tang China later conquered the Turkic tribes of the region, and Sogdians such as An Lushan played a major role at the Chinese court until the An Lushan Rebellion. Zoroastrianism, Manichaeism, Buddhism, and Nestorian Christianity were the main faiths of the Sogdians until the Muslim conquest of Transoxania, after which the Sogdians were gradually converted to Islam. By the end of the Samanid Empire in 999, the Sogdian language had been replaced by Persian, and the Sogdians were either assimilated as Persians or came to identify as "Yaghnobi" Tajiks.