The recorded history of Andhra Pradesh, one of the 28 states of 21st-century India, begins in the Vedic period. It is mentioned in Sanskrit epics such as the Aitareya Brahmana (800 BCE). Its sixth-century BCE incarnation Assaka lay between the Godavari and Krishna Rivers, one of sixteen mahajanapadas (700–300 BCE). The Satavahanas succeeded them (230 BCE–220 CE), built Amaravati, and reached a zenith under Gautamiputra Satakarni. The Lok Sabha formed Telangana from ten districts of Andhra Pradesh on 18 February 2014.