In 1406,^[36] Burmese forces from the Kingdom of Ava invaded Arakan. The control of Arakan was part of the Forty Years' War between Ava and Hanthawaddy Pegu on the Burmese mainland. The control of Arakan would change hands a few times before Hanthawaddy forces drove out Ava forces in 1412. Ava would retain a toehold in northern Arakan until 1416/17 but did not try to retake Arakan. The Hanthawaddy influence ended after King Razadarit's death in 1421. The former Arakanese ruler Min Saw Mon received asylum in the Bengal Sultanate and lived there in Pandua for 24 years. Saw Mon became close to the Bengal Sultan Jalaluddin Muhammad Shah, serving as a commander in the king's army. Saw Mon convinced the sultan to help restore him to his lost throne.^[37]

Saw Mon regained control of the Arakanese throne in 1430 with military assistance from Bengali commanders Wali Khan and Sindhi Khan. He later founded a new royal capital, Mrauk U. His kingdom would become known as the Mrauk U Kingdom. Arakan became a vassal state of the Bengal Sultanate and recognized Bengali sovereignty over some territory of northern Arakan. In recognition of his kingdom's vassal status, the kings of Arakan received Islamic titles, despite being Buddhists, and legalized the use of Islamic gold dinar coins from Bengal within the kingdom. The kings compared themselves to Sultans and employed Muslims in prestigious positions within the royal administration. Saw Mon, now styled as Suleiman Shah died in 1433, and was succeeded by his younger brother Min Khayi.

Though started out as a protectorate of the Bengal Sultanate from 1429 to 1531, Mrauk-U went on to conquer Chittagong with the help of the Portuguese. It twice fended off the Toungoo Burma's attempts to conquer the kingdom in 1546–1547, and 1580–1581. At its height of power, it briefly controlled the Bay of Bengal coastline from the Sundarbans to the Gulf of Martaban from 1599 to 1603.^[38] In 1666, it lost control of Chittagong after a war with the Mughal Empire. Its reign continued until 1785, when it was conquered by the Konbaung dynasty of Burma. It was home to a multiethnic population with the city of Mrauk U being home to mosques, temples, shrines, seminaries and libraries. The kingdom was also a center of piracy and the slave trade. It was frequented by Arab, Danish, Dutch and Portuguese traders.