The Shaishunaga dynasty (IAST: Śaiśunāga, literally "of Shishunaga") is believed to have been the third ruling dynasty of Magadha, an empire of ancient India. According to the Hindu Puranas, this dynasty was the second ruling dynasty of Magadha, succeeding Nagadashaka of the Haryanka dynasty.
Shishunaga, the founder of the dynasty, was initially an amatya or "minister" of the last Haryanka dynasty ruler Nāgadāsaka and ascended to the throne after a popular rebellion in c. 421 BCE. The capital of this dynasty initially was Rajgir; but later shifted to Pataliputra, near the present day Patna, during the reign of Kakavarna. According to tradition, Kakavarna was succeeded by his ten sons. This dynasty was succeeded by the Nanda Empire in c. 345 BCE.
Shishunaga founded his dynasty in 413 BCE with its capital in Rajgir and later Pataliputra (both in what is now Bihar). Buddhist sources indicate that he had a secondary capital at Vaishali, formerly the capital of Vajji, until it was conquered by Magadha. The Shaishunaga dynasty ruled one of the largest empires in the Indian subcontinent.Most important achievement of Shisunga was destruction of the pradyota dyanasty of Avanti.This brought to an end the hundred year old rivalry between Magadha and Avanti . From then Avanti became a part of Magadha rule
According to the Puranas, Shishunaga was succeeded by his son Kakavarna and according to the Sinhala chronicles by his son Kalashoka. On the basis of the evidence of the Ashokavadana, Hermann Jacobi, Wilhelm Geiger and Ramakrishna Gopal Bhandarkar concluded that both are the same. During Shishunaga's reign, he was the governor of Varanasi. The two most significant events of his reign are the Second Buddhist council at Vaishali in 383 BC and the final transfer of the capital to Pataliputra. According to the Harshacharita, he was killed by a dagger thrust into his throat in the vicinity of his capital. According to Buddhist tradition, he had nine or ten sons, who were ousted by Ugrasena Nanda.
According to tradition,[which?] ten sons of Kalashoka ruled simultaneously. The Mahabodhivamsa states their names as Bhadrasena, Korandavarna, Mangura, Sarvanjaha, Jalika, Ubhaka, Sanjaya, Koravya, Nandivardhana and Panchamaka. Only one of them is mentioned in the Puranic lists, Nandivardhana.
The Puranas list Nandivardhana as the ninth Shaishunaga king and his son Mahanandin as the tenth and the last Shaishunaga king. Mahanandin was killed by his illegitimate son from a Shudra wife named Mahapadma.