The ancient part of Samarkand situated on Afrasiab hill was named after legendary Turanian king. The settlement arose in the 8th - early 7th centuries B.C.; it occupied more than 200 hectares and was protected by river canals in the north and east and deep ravines in the south. In the time of the Achaemenids the city was encircled with a massive wall which had inside corridor and towers. Many scientists identify Afrasiab with ancient Sogdian capital - Marakanda destroyed by Alexander the Great in the 4th century B.C. Samarkand rose again in the 4th-8th centuries when the Great Silk Road became an important trade route. Samarkand became the strongest of Sogdian princedoms. In the 5th-7th centuries it was governed by the Hephthalites and Turks. In the 7th-8th centuries Samarkand recognized supremacy of Chinese Tang dynasty. Four lines of new walls were built around Samarkand in that period. There were built Zoroastrian, Buddhist and Christian temples. The wall paintings in the royal palace are still safe. In the 8th century Arabian troops headed by Quteiba conquered Samarkand.