Tenshō Iga War

This, plus the distance of the region from major transportation routes, meant that Iga was easily defendable by a relatively small number of men and was not a priority target for outside forces.

[1] The Niki clan had served as shugo of the province for the Ashikaga shogunate, but their control had never been strong and soon weakened further as the shōgun's authority diminished.

No great warlord rose to take their place, although the Rokkaku to the north and the Kitabatake to the east extended their influence over parts of the province.

Following the Battle of Okehazama in 1560, Oda Nobunaga of Owari province began his rise as a prominent daimyō of central Japan, rapidly expanding his territory.

As part of the peace agreement, Tomofusa adopted Nobunaga's son Nobukatsu as his heir, ceding much of his authority to the Oda.

In December 1576 Nobunaga and Nobukatsu assassinated most of the remaining Kitabatake leadership (the Mise Incident), cementing their control of Ise.

The waiting Iga troops made heavy use of their knowledge of the terrain and guerrilla tactics to surprise and confuse Nobukatsu's army.

[15] Oda Nobunaga himself toured the conquered province in early November 1581, and then withdrew his troops, placing control in Nobukatsu's hands.

[16][17] The espionage and guerrilla tactics developed by the Iga "militias of warrior-peasants" are believed to have formed the basis for the "ninja" tradition of the region.