From the Mauryan period, Northern Black Polished Ware, copper coins, terracotta ring wells and ivory seals with Brahmi text have been excavated at Ujjain. Ujjain emerged as an important commercial centre, partially because it lay on the trade route connecting north India to the Deccan, starting from Mathura. It also emerged as an important center for intellectual learning among Jain, Buddhist and Hindu traditions. After the Mauryans, Ujjain was controlled by a number of empires and dynasties, including local dynasties, the Shungas, the Western Satraps, the Satavahanas, and the Guptas.