a tributary in 1371. In the west, Ava's candidate to Arakan's throne became king in 1373/74. In 1385, Ava looked south where the throne of Hanthawaddy Pegu had just been taken by a 16-year-old Razadarit, who launched a war that would go on for another 40 years. Razadarit proved quite able, however, to meet Ava's challenge. By 1391, he had not only repelled Ava's invasions but also recaptured Martaban which had been in revolt since 1364. Ava and Pegu entered into a truce in 1391. But when Ava's new king Minkhaung I faced multiple rebellions in 1401, Razadarit took this as an opportunity to invade the upcountry with a large naval force. But Ava's defences held, and the two sides reached another truce in 1403. After the second truce with Pegu, Ava resumed its acquisition spree elsewhere. By late 1406, its armies had taken Arakan in the west and Mohnyin in the north. It proved too much for Pegu as it could not let Ava get too strong. Razadarit again broke the truce in 1408 by driving out Ava's garrison in Arakan. He also got the Shan state of Theinni (Hswenwi) to attack Ava from the north. Ava fought off attacks from both sides, and by 1410, under the leadership of Crown Prince Minye Kyawswa, began to gain an upper hand. Minye Kyawswa decisively defeated Theinni and its Chinese troops in 1412. With the rear secure, the prince invaded the Hanthawaddy country in full force in 1414. He was on the cusp of victory when he was killed in action in 1415. The war lost steam after Minye Kyawswa's death, and ended soon after both Minkhaung and Razadarit died in 1421. Rise of Mrauk-U Another key development in the wake of the Forty Years' War was the emergence of a unified and powerful Arakan. The western littoral between the Arakan Yoma and the Bay of Bengal remained politically fragmented even after Pagan's fall. The coast was divided between at least two power centres at Launggyet in the north and Sandoway (Thandwe) in the south. The weakness became exposed between 1373 and 1429 when the region was first subject first to Avan and then to Peguan interference. Arakan was Pegu's vassal from 1412 at least until Razadarit's death in 1421. The restoration came in 1429 when the last king of Arakan, Saw Mon III, in exile since 1406, came back with