Kublai Khan emerged triumphant from the civil war which attended his accession, but only at the expense of the Mongol Empire’s fracture, with Kublai holding at best nominal sway over the three western khanates. But China was the prize and by 1279, he completed its conquest with the elimination of the Southern Song. Kublai Khan has to be one of the least successful generalissimos in the history of naval warfare. Two massive armadas sent to conquer Japan (1274, 1281) were devastated by typhoons, the landing forces marooned and annihilated. The fleet sent to invade Java managed to stay afloat, only for the army to be ambushed by a supposed ally after landing, The most esoteric disaster occurred in Annam (1285), where the Mongol fleet was entrapped by a forest of spiked poles planted in the bed of a river, then massacred. When he stayed on dry land, Kublai tended to have more success.
— OR —