Sena dynasty, Indian dynasty ruling in Bengal in the 11th and 12th centuries ce. Their ancestors came from the south and established themselves as chieftains in southwestern Bengal early in the 11th century. Hemantasena, the founder of the dynasty, was originally a tributary of the Pala dynasty. In the mid-11th century he declared his independence and set himself up as king. His successor, Vijayasena (reigned c. 1095–1158), built an empire on the ruins of that of the Palas, gaining control of all Bengal and northern Bihar.
Sena rule in Bengal brought about a marked revival of orthodox Hinduism. The caste system, which had become lax because of the Buddhist influence of the Palas, was reestablished, and the Bengali system of hypergamy, the socially upward marriage of women, was reputedly founded by the Sena king Vallalasena. The last Sena king, Lakshmanasena (reigned c. 1178– c. 1205), became a great patron of literature; the poets Jayadeva and Dhoyi wrote at his court at Nadia. Lakshmanasena was expelled from Nadia in 1202 by the Turkish chief Muḥammad Bakhtyār Khaljī and died about three years later. Sena kings continued to rule in eastern Bengal for some decades, but the main political power in Bengal passed to the Muslims.