The ancient Indian kingdom where the Buddha spent much of his teaching career was Magadha.
Magadha occupied part of the middle Ganges plain in what is now Bihar, India. During the Buddha’s lifetime, it was one of the most powerful states in northern India. Its rulers, including Bimbisara and Ajatashatru, are prominent in Buddhist literary traditions.
Important Buddhist sites connected with Magadha include Rajgir, the kingdom’s early capital, and the later capital Pataliputra. The Buddha is traditionally said to have taught at Rajgir and at nearby Vulture Peak. The region also includes Bodh Gaya, associated with his enlightenment, although the ancient political and geographical contexts changed over time.
Magadha later became the core of the Mauryan Empire under Chandragupta Maurya and Ashoka. It is sometimes confused with Kosala, another major kingdom associated with the Buddha’s teaching career, especially through the city of Shravasti.