Shungas and Kanvas are considered important ruling dynasties of post-Mauryan period.
After Asoka the Great, the later Muaryas were not able enough to keep the large empire intact. The last Mauryan ruler Brihadratha was not a strong ruler and during a military parade, his army general Pushyamitra Shunga assassinated him and thus the Maurya dynasty came to an end.
Shunga dynasty was founded by Pushyamitra Shunga in 185-183 BC. Its capital was Patliputra and later on Vidisha became the capital of later Shunga rulers. Shungas were the contemporaries of Saatvahanas, Pandyas, Cholas and Cheras. Important rulers of Sunga Dynasty were Pushyamitra Sunga, Agnimitra, Bhagabhadra and Devabhuti.
Pushyamitra Sunga ruled for 36 years. He was succeeded by his son Agnimitra who was the hero of Malvikagnimitram of Kalidasa. Devabhuti was the last Shunga Ruler. He was murdered by his own minister Vasudeva Kanva in 73 BC and thus Kanva Dynasty was founded.
The Kanvas were Brahmins by caste and were believed to be descendents from Rishi Kanva. Bhimimitra succeeded Vasudeva. The dynasty was later on overthrown by the Satavahana dynasty. The important four kings of Kanva dynasty were namely Vasudeva, Bhumimitra, Narayana and Susharman.