The Tensho Iga Wars: From Nobukatsu’s Defeat to Oda Control

In 1579, Nobukatsu’s force entered Iga and was defeated. Two years later, in 1581, the Oda side attacked and Iga’s defenders were defeated. The same region witnessed different outcomes.

The shape of its mountains and passes cannot, by itself, explain that change. Nobukatsu’s effort to establish a foothold, local resistance, the later movement of several Oda forces and the establishment of rule all need to be considered.

Separating the two years provides a way into that process. The comparison concerns the relationship between regional organization and a larger political power as well as the fighting conducted by individual forces.

Maruyama Castle appears in the prehistory of the campaigns. The official Japan Heritage explanation says a retainer of Nobukatsu built it in 1578 and that Iga forces captured it in the same year.

The account places an Oda attempt to create a foothold opposite local efforts to stop it. It also describes earthwork enclosures and traces of stone construction at the present site, without establishing that every surviving feature belongs to that initial episode.

The sources differ: the museum material catalogued on Iga’s ADEAC site describes rebuilding in 1578 and capture in 1579. That discrepancy is left unresolved. Nor should the castle at Hijikigawa and Shimokanbe be equated by name alone with the Niki castle also called Maruyama in the Ueno area.

The same volume preserves the text of a message from Nobunaga reprimanding Nobukatsu for moving troops without consultation. The campaign therefore also raises a question about initiative and authority within the Oda house.

A communication from father to son appears alongside the account of defeat. The article follows the reprimand as it is transmitted in this printed edition, without treating the nineteenth-century page as Nobunaga’s autograph letter.

The failure of 1579 and the operation of 1581 should consequently not be collapsed into one unchanging attempt. Their relationship involves a different scale and coordination of military action, rather than the simple repetition of the earlier campaign.

The named approaches include Koka, Shigaraki, Kabuto and Yamato. The forces heading into Iga were not entering from only one location. Different commanders are assigned to different approaches in the text.

The surrounding mountains therefore formed a landscape with several points of military entry. Recognizing those relationships is useful without assuming that present roads reproduce every section of the historical journeys.

The article does not turn the selected list into an independently verified complete set of routes. The next entry adds another movement: forces from separate approaches came together within the operation.

The ninth-month passages include attacks on castles, the dispersal of defenders and the burning of temples and shrines. The effects of the campaign extended beyond the immediate positions occupied by armed forces.

Shincho Koki follows the Oda side’s movements, and that perspective must remain visible. Even within its account, however, Iga appears as a region under attack. No independently established total of civilian victims, complete destruction or universal death is supplied here.

The aftermath offers another line of inquiry. A Mie University lecture abstract by Takigawa Kazuya discusses recovery through records such as building inscriptions associated with Kotengu Seizo. That perspective cannot turn the dates of surviving Buddhist statues into a direct calculation of wartime losses.

After the ninth-month military operations, the tenth-month entries describe Nobunaga himself entering Iga. They record his inspection of the region, visits to positions associated with Nobukatsu and others, and instructions concerning fortified sites.

The chronicle presents the commanders’ earlier operations and Nobunaga’s later inspection at different times. His subsequent presence should not be projected backwards into a claim that he personally fought at the head of the initial advance.

The account had moved from forces entering and attacking places to inspection and the arrangement of strongpoints for a new political order. That continuation marks another difference from the entry ending in Nobukatsu’s defeat in 1579.