Hokkaido, formerly known as Ezo, is the northernmost and second-largest of the Japanese Home Islands, as well as the northernmost prefecture of Japan. The island is separated from the Japanese mainland of Honshu by the Tsugaru Strait, and they are connected by the undersea railway Seikan Tunnel. Hokkaido's capital (and only major city) in Sapporo.
Hokkaido was originally settled by the Ainu, Nivkhs, and Oroks, and the Japanese first came into contact with the island from 658 to 660, when Abe no Hirafu and his large army and fleet made contact with the locals. The Ezo people conducted trade with the Japanese, obtaining rice and iron from the Japanese. In 1457, Takeda Nobuhiro killed the Ainu leader Koshamain, and his descendants became the Matsumae clan, which had authority over the south of Hokkaido until the fall of the Tokugawa Shogunate. In 1868, the island was occupied by Tokugawa loyalists, who proclaimed the creation of the Republic of Ezo, the first attempt at democracy in Japan. The republic was crushed by the Emperor's forces, and the island was renamed into Hokkaido in 1869 and was divided into new regional subdivisions.
Hokkaido is known for its cool summers and icy/snowy winters, and much of its climate consists of snowy taiga/boreal forest. In 2016, Hokkaido had a population of 5,377,435 people.