One of the four chief kingdoms of India at the time of the Buddha, the others being Kosala, the kingdom of the Vaṃsas and Avanti. Māgadha formed one of the sixteen Mahājanapadas and had its capital at Rājagaha or Giribbaja where Bimbisāra, and after him Ajātasattu, reigned. Later, Pāṭaliputta became the capital. By the time of Bimbisāra, Aṅga, too, formed a part of Māgadha, and he was known as king of Aṅga Māgadha. Thus Bimbisāra sends for Soṇa Koḷivisa, a prominent citizen of Campā, capital of Aṅga. Vin.i.27 In the Buddha’s day, Māgadha consisted of eighty thousand villages. Vin.i.179
Ajātasattu succeeded in annexing Kosala with the help of the Licchavis, and he succeeded also in bringing the confederation of the latter under his sway; preliminaries to this struggle are mentioned in the books. DN.ii.73f. DN.ii.86
At the time of the Buddha, the kingdom of Māgadha was bounded on the east by the river Campā, on the south by the Vindhyā Mountains, on the west by the river Soṇa, and on the north by the Ganges. The latter river formed the boundary between Māgadha and the republican country of the Licchavis, and both the Māgadhas and the Licchavis evidently had equal rights over the river.
During the early Buddhist period Māgadha was an important political and commercial centre, and was visited by people from all parts of Northern India in search of commerce and of learning. The kings of Māgadha maintained friendly relations with their neighbours, Bimbisāra and Pasenadi marrying each other’s sisters. When Candappajjota of Ujjeni was suffering from jaundice, Bimbisāra sent him his own personal physician, Jīvaka.
In Māgadha was the real birth of Buddhism (see, e.g., the words put in the mouth of Sahampati: pātur ahosi Magadhesu pubbe dhammo Vin.i.5 ), and it was from Māgadha that it spread after the Third Council. The Buddha’s chief disciples, Sāriputta and Moggallāna, came from Māgadha. The cornfields of Māgadha were rich and fertile. Thag.208
The names of several places in Māgadha occur in the books—e.g., Ekanālā, NāIakagāma, Senānigama, Khāṇumata, Andhakavindha, Macala, Matula, Ambalaṭṭhikā, Pāṭaligāma, NāIandā and SāIindiya.
Māgadha is identified with the modern South Behar.