The Battle of Nagashino was a famous battle in Japanese history, fought in 1575 at Nagashino in Mikawa Province. The allied forces of Oda Nobunaga and Tokugawa Ieyasu (38,000) fought against Takeda Katsuyori's forces (15,000) and the allied forces won a crushing victory over the Takeda clan. As a result, Oda Nobunaga's unification of Japan was seen as certain.

Nagashino Castle was a Sengoku period Japanese castle located in what is now Shinshiro, eastern Aichi Prefecture, Japan. It is noteworthy as the site of the crucial Battle of Nagashino between the combined forces of Tokugawa Ieyasu and Oda Nobunaga against Takeda Katsuyori in 1575. The ruins have been protected as a National Historic Site since 1929, the first time a former castle site had received such protection.