Rise of Magadha and Alexander's invasion

Magadha rose from one mahajanapada among sixteen to the dominant power of northern India through geography, resources, armies and ambitious kings. Its capitals Rajgir and later Pataliputra sat on trade routes and near iron deposits, and rulers from Bimbisara to the Nandas built the revenue and military base that the Mauryas inherited. Alexander's invasion in the northwest in 326 BCE, though brief, exposed the political fragmentation of the Punjab and left Greek accounts that illuminate Indian kingship and warfare.