Battle of Omosu

Date	1580
Location	coast of the Izu peninsula
Result	Hōjō victory

Belligerents

Hōjō forces

Takeda forces

Commanders and leaders

Hōjō Ujimasa

Takeda Katsuyori

Campaigns of the Takeda

Campaigns of the Hōjō

Arai Edo Nashinokidaira Kamakura Ozawahara Musashi-Matsuyama 1537 Kawagoe (1537) Kōnodai 1538 Kawagoe (1545) Odawara 1561 Musashi-Matsuyama 1563 Kōnodai 1564 Hachigata 1568 Odawara 1569 Mimasetoge Kanbara Nirayama Fukazawa Omosu Kanagawa Hachigata 1590 Odawara 1590 Shimoda Oshi

The 1580 battle of Omosu was one of many battles fought between the Hōjō and Takeda clans during Japan's Sengoku period. It is distinguished, however, as one of the very few naval battles to be fought in pre-modern Japan.

The battle took place off the coast of the Izu peninsula between the navies of Hōjō Ujimasa, the head of the Hōjō, and those of Takeda Katsuyori, the head of the Takeda. While the navies faced off, the land armies of each family advanced towards one another. In the end, the Hōjō were victorious.

References

Turnbull, Stephen (1998). 'The Samurai Sourcebook'. London: Cassell & Co.