The Shunga empire's capital was Pataliputra, but later emperors such as Bhagabhadra also held court at Besnagar (modern Vidisha) in eastern Malwa.

However, after the death of Agnimitra, the second king of the dynasty, the empire rapidly disintegrated:[6] inscriptions and coins indicate that much of northern and central India consisted of small kingdoms and city-states that were independent of any Shunga hegemony.

They fought the Kalinga, the Satavahana dynasty, the Indo-Greek kingdom and possibly the Panchalas and Mitras of Mathura.

The Bharut epigraph appears on a pillar of the gateway of the stupa, and mentions its erection "during the rule of the Sugas, by Vatsiputra Dhanabhuti".

[25] Some ancient sources however claim a greater extent for the Shunga empire: the Asokavadana account of the Divyavadana claims that the Shungas sent an army to persecute Buddhist monks as far as Sakala (Sialkot) in the Punjab region in the northwest: ... Pushyamitra equipped a fourfold army, and intending to destroy the Buddhist religion, he went to the Kukkutarama (in Pataliputra).

Following the Mauryans, the first Sunga emperor, a Brahmin named Pushyamitra,[27] is believed by some historians to have persecuted Buddhists and contributed to a resurgence of Brahmanism that forced Buddhism outwards to Kashmir, Gandhara and Bactria.

Pushyamitra is known to have revived the supremacy of the Bramahnical religion and reestablished animal sacrifices (Yajnas) that had been prohibited by Ashoka.

[33] Some writers believe that Brahmanism competed in political and spiritual realm with Buddhism[28] in the Gangetic plains.

The existence of Buddhism in Bengal in the Shunga period can also be inferred from a terracotta tablet that was found at Tamralipti and is on exhibit at the Asutosh Museum in Kolkata.

Two dedications by a king named Brahmamitra as well as the monarch Indragnimitra are recorded at the Mahabodhi Temple in Bodh Gaya.

As regards the first coping inscription, he has found traces of eleven Brahmi letters after "Kuramgiye danam", the first nine of which read "rajapasada-cetika sa".

Bloch reads these nine letters as "raja-pasada-cetikasa" and translates this expression in relation to the preceding words: "(the gift of Kurangi, the wife of Indragnimitra and the mother of living sons), "to the caitya (cetika) of the noble temple", taking the word raja before pasada as an epithet on ornans, distinguishing the temple as a particularly large and stately building similar to such expressions as rajahastin 'a noble elephant', rajahamsa 'a goose' (as distinguished from hamsa 'a duck'), etc.

"Cunningham has translated the expression "the royal palace, the caitya", suggesting that "the mention of the raja-pasada would seem to connect the donor with the king's family."

On the basis of Ashokavadana, it is presumed that the stupa may have been vandalised at one point sometime in the 2nd century BCE, an event some have related to the rise of the Shunga emperor Pushyamitra who overtook the Mauryan empire as an army general.

The dome was set on a high circular drum meant for circumambulation, which could be accessed via a double staircase.

[41][43] The style of the Shunga period decorations at Sanchi bear a close similarity to those of Bharhut, as well as the peripheral balustrades at Bodh Gaya, which are thought to be the oldest of the three.

[citation needed] The Shunga empire's wars with the Indo-Greek kingdom figure greatly in the history of this period.

From around 180 BCE the Greco-Bactrian ruler Demetrius conquered the Kabul Valley and is theorised to have advanced into the trans-Indus to confront the Shungas.

[citation needed] Several works, such as the Mahabharata and the Yuga Purana describe the conflict between the Shungas and the Indo-Greeks.

[51] The Indo-Greeks, called Yavanas in Indian sources, either led by Demetrius I or Menander I, then invaded India, possibly receiving the help of Buddhists.

The Hindu text of the Yuga Purana, which describes Indian historical events in the form of a prophecy,[53][note 1] relates the attack of the Indo-Greeks on the Shunga capital Pataliputra, a magnificent fortified city with 570 towers and 64 gates according to Megasthenes,[55] and describes the impending war for city: Then, after having approached Saketa together with the Panchalas and the Mathuras, the Yavanas, valiant in battle, will reach Kusumadhvaja "the town of the flower-standard", Pataliputra.

[60][61] The inscription is important in that it mentions the date of its dedication as "The last day of year 116 of Yavana hegemony (Yavanarajya)".

It is considered that this inscription is attesting the control of the Indo-Greeks in the 2nd and 1st centuries BCE in Mathura, a fact that is also confirmed by numismatic and literary evidence.

[25] The Anushasana Parva of the Mahabharata affirms that the city of Mathura was under the joint control of the Yavanas and the Kambojas.

The Indo-Greeks and the Shungas seem to have reconciled and exchanged diplomatic missions around 110 BCE, as indicated by the Heliodorus pillar, which records the dispatch of a Greek ambassador named Heliodorus, from the court of the Indo-Greek king Antialcidas, to the court of the Shunga emperor Bhagabhadra at the site of Vidisha in central India.

After the death of Agnimitra, the second king of the dynasty, the empire rapidly disintegrated:[6] inscriptions and coins indicate that much of northern and central India consisted of small kingdoms and city-states that were independent of any Shunga hegemony.

[22] According to the Puranas: "The Andhra Simuka will assail the Kanvayanas and Susarman, and destroy the remains of the Sungas' power and will obtain this earth.

This work was composed by Kalidasa in the later Gupta period, and romanticised the love of Malavika and King Agnimitra, with a background of court intrigue.

During the historical Shunga period (185 to 73 BCE), Buddhist activity also managed to survive somewhat in central India (Madhya Pradesh) as suggested by some architectural expansions that were done at the stupas of Sanchi and Bharhut, originally started under Emperor Ashoka.

It remains uncertain whether these works were due to the weakness of the control of the Shungas in these areas, or a sign of tolerance on their part.