Lord Buddha spent a significant portion of his life and ministry in the kingdoms of Kosala and Magadha. His birthplace, Lumbini, was near Kosala. He attained enlightenment and delivered most of his sermons in Magadha, particularly in places like Bodh Gaya, Sarnath, and Rajgir. While Avanti and Gandhara were important kingdoms of the period, they were not as directly associated with the key events of Buddha's life as Kosala and Magadha.