For its first 100 years, the kingdom was merely a loose collection of three Mon-speaking regions. The high kings at the capital had little substantive authority over the vassals. Indeed, Martaban was in open rebellion from 1363 to 1389. A more centralised rule came with the reign of King Razadarit, who not only firmly unified the three Mon-speaking regions together but also successfully fended off the northern Burmese-speaking Kingdom of Ava in the Forty Years' War (1385–1424). The war ended in a stalemate but it was a victory for Hanthawaddy as Ava finally gave up its dream of restoring the Pagan Empire. In the years following the war, Pegu occasionally aided Ava's southern vassal states of Prome and Toungoo in their rebellions but carefully avoided getting plunged into a full-scale war.