Excerpts from Books and Wikipedia
"In 1264, Kublai Khan took Beijing to seize control of northern China and battled the remains of the Sung dynasty in the south. The Sung's ally, the Emperor of Japan, HijoTokimune, was Kublai Khan's next target. . . . Archeology has suggested that their flat-bottomed boats were for river use, and unsuitable for storms at sea. The second defeat ended the Mongol aspirations of expansion, and was celebrated in Japan as being the results of a kami kaze ('divine wind')." [Furtado: 1001 Days]