The Shaishunaga dynasty (IAST: Śaiśunāga, literally "of Shishunaga") was possibly the second ruling dynasty of Magadha. According to the Buddhist text Mahavamsa, this dynasty was the second ruling dynasty of Magadha, succeeding Nagadashaka of the Haryanka dynasty. The Brahminic Puranas have given a different list with different chronology of the Shaishunaga dynasty kings, whereas Jain texts do not mention this dynasty.
History
Shishunaga was the founder of the dynasty. He was initially an amatya or "minister" of the last Haryanka dynasty ruler Nāgadāsaka and ascended to the throne after a popular rebellion in c. 413 BCE.
The capital of this dynasty initially was Vaishali; but later shifted to Pataliputra, near the present day Patna, during the reign of Kalashoka.
According to tradition, Kalashoka was succeeded by his ten sons. This dynasty was succeeded by the Nanda dynasty in c. 345 BCE.
Historicity
Jain texts have skipped over the Shaishunaga dynasty. They mention instead that Udayin (of the preceding Haryanka dynasty) was killed by an assassin of rival kingdom. Being childless, he was succeeded by Nanda who was selected by his ministers.
Historian K. T. S. Sarao — who favors the Buddhist "short chronology" — has dated Udayin's reign to c. 373-357 BCE, i.e., only a short time before the Nanda dynasty which preceded Chandragupta Maurya. Sarao has suggested that the kingdom of Magadha became divided after Udayin's death: with the "suspicious" lists of different successors listed in various texts possibly having ruled in different locations simultaneously instead of one after another, until the kingdom was re-unified. Similarly, Keay — another proponent of the Short Chronology — states that there is great uncertainty about the royal succession for this period, probably because there was a period of "court intrigues and murders," during which "evidently the throne changed hands frequently, perhaps with more than one incumbent claiming to occupy it at the same time" until Mahapadma Nanda was able to secure the throne.
Rulers
Shishunaga
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. Shishunaga ended the Pradyota dynasty of Avanti, ending the centuries-old rivalry between their kingdoms and annexing Avanti into Magadha.
Kakavarna/Kalashoka
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.
Later rulers
According to Buddhist tradition, 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.
According to the Bhagavata Purana, Kākavarṇa was succeeded by seven kings and lists them as following; Kṣemadharmā, Kṣetrajña, Vidhisāra, Ajātaśatru, Darbhaka, Ajaya, Nandivardhana, and Mahanandin.
Other Puranas list Nandivardhana as the ninth Shaishunaga king and his son Mahanandin as the tenth and the last Shaishunaga king. Mahanandin was killed by Mahapadma, his illegitimate son .
Decline
According to Puranas, Shaishunagas were followed by the Nanda Empire, which was founded by Mahanandin's son Mahapadma Nanda.