Bangladesh has a long history that can be divided into pre-historic, ancient, medieval, and modern periods. The ancient period saw rule by the Maurya, Gupta, Pala, and Sena empires from the 6th century BC to the 12th century AD. The medieval period was defined by Muslim sultanates and the Mughal Empire between the 13th and 18th centuries. The modern age brought British colonial rule from the 18th century until Bangladesh gained independence in 1971 after the Pakistan period.