Bengal remained relatively stable and prosperous during the 17th century. A key challenge during the early Mughal period was piracy from the Kingdom of Mrauk U and the Portuguese settlement in Chittagong. In 1666, the Mughal Empire-Kingdom of Mrauk U War expelled the Arakanese and Portuguese from Chittagong. The Mughals also engaged in the Ahom-Mughal conflicts. During the 18th century, Bengal endured the invasions by the Maratha Army- the military of the Maratha Confederacy. It fell to the conquest of the British East India Company after the Battle of Plassey.