Tibetan scholar Taranatha,kalachakra

 Buddhist books reveal that Andhras established their kingdoms on the Godavari belt at that time. Asoka referred in his 13th rock edict that Andhras were his subordinates. Inscriptional evidence shows that there was an early kingdom in coastal Andhra ruled by Kuberaka, with Pratipalapura (Bhattiprolu) as his capital. This is probably the oldest known kingdom in Southern India. Around the same time Dhanyakatakam/Dharanikota (present day Amaravati) appears to have been an important place, which was visited by Gautama Buddha. According to the ancient  “On the full moon of the month Chaitra in the year following his enlightenment, at the great stupa of Dhanyakataka, the Buddha emanated the mandala of ‘The Glorious Lunar Mansions’ (Kalachakra)”.