During the Achaemenid period, Sogdiana and Bactria were part of the Persian empire. Sogdians and Bactrians occupied important positions in the administration and military of the Achaemenid Empire  After the Persian Empire was defeated by Alexander the Great, Bactria, Sogdiana and Merv, being part of Persian Empire, had to defend themselves from new invaders. In fact, the Macedonians faced very stiff resistance under the leadership of Sogdian ruler Spitamenes. Alexander the Great managed to marry Roxana, the daughter of a local ruler, and inherited his land. Following Alexander's brief occupation, the Hellenistic successor states of the Seleucids and Greco-Bactrians controlled the area for another 200 years in what is known as the Greco-Bactrian Kingdom. During the time period from 90 BC to 30 BC, Yuezhi destroyed the last Hellenistic successor states and, together with the Tokhari, (to whom they were closely related) created a Kushan Empire around 30 AD. For another 400 years, until 410 AD, the Kushan Empire was a major power in the region along with the Roman Empire, the Parthian Empire and the Han Empire (China). Notable contact was made with local peoples when the envoys of the Han Dynasty journeyed to this area in the 2nd century BC. At the end of the Kushan period, the Empire became much smaller and would have to defend itself from the powerful Sassanid Empire that replaced the Parthian Empire. The famous Kushan king Kanishka promoted Buddhism and during this time Buddhism was exported from Central Asia to China. The Sassanids once controlled much of what is now Tajikistan, but lost the territory to the Hephthalites (possibly also of Iranian descent) during the time of Peroz I. They created a powerful empire that succeeded in making Iran a tributary state around 483–485. Shah of Persia Peroz fought three wars with Hephthalites. During the first war he was captured by Hephthalite army and later was released after Byzantine emperor paid a ransom for him. During the second war Peroz was captured again and was released after paying a huge contribution to the Hephthalite king. During the third war Peroz was killed. The Hephthalites were subjugated in 565 by a combination of Sassanid and Kök-Turk forces. Subsequently, present Tajikistan was ruled by Göktürks and Sassanids, however when the Sassanid Empire fell the Turks kept control of Tajikistan but they later lost it to the Chinese people, however, they later managed to take control of Tajikistan once again, only to lose it to the Arabs in 710.