The Nanda dynasty ruled in northern part of the Indian subcontinent during the 4th century BCE, and possibly during the 5th century BCE. In 326 BC, Alexander invaded India, after crossing the river Indus he advanced towards Taxila.
Lion was one of the motifs used in Ashokan pillars. Lion is a solar symbol and it also represents the Buddha, as he is referred to as Sakyasimha which also means a lion among the Sakyas.