In the Battle of Vatapi, the Pallava ruler Narsimhavarman I defeated and killed Pulakesin II and captured the Chalukyan capital, Badami in 642 AD. Thus, he assumed the title of ‘Vatapikonda’ (Conqueror of Vatapi).
Viharas were for the purpose of living, Chaityas were assemblies for the purpose of discussions. Further, Chaityas were with Stupas, Viharas did not have stupas.