After the failed first invasion by the Yuan navy, the Japanese made many defense preparations, constructing numerous fortifications along the coast.

In early 1280 Kublai Khan planned another invasion of Japan and ordered his shipbuilders to rebuild the whole fleet within a year.

The Eastern Route Army arrived at Hakata Bay on June 23, and decided to proceed with the invasion without waiting for the larger Southern force which had still not left China.

They were a short distance to the north and east of where their force had landed in 1274, and were in fact beyond the walls and defenses constructed by the Japanese.

This harassing tactic led the Yuan forces to retreat to Tsushima, where they would wait for the Southern Route Army.

On August 15 a major tempest struck the Tsushima Straits, lasting two full days and destroying most of the Yuan fleet.

Contemporary Japanese accounts indicate that over 4,000 ships were destroyed in the storm; 80% of the Yuan soldiers either drowned or were killed by samurai on the beaches.

[3] The Japanese army lost 300 soldiers but defeated Hong Dagu, who nearly died in this battle, and Zhang Cheng.