The Capital of Magadh empire was situates at Rajgriha or Girivraja. The city was almost impregnable as it was surrounded by five hills, the openings in which were closed by stone walls on all sides.
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.