Ishiyama Hongan-ji War

Siege of Ishiyama Hongan-ji
Part of the Sengoku period
The battle of Ishiyama Hongan-ji by Utagawa Yoshifuji (1828-1887)
Date August 1570 – August 1580 Location Osaka, Fortress of Ishiyama Hongan-ji; other ikki strongholds Result Oda victory, Kōsa surrenders
Belligerents
forces of Oda Nobunaga	Ikkō-ikki monks forces of Ashikaga Yoshiaki[1] Mōri clan
Commanders and leaders
Oda Nobunaga Sakuma Nobumori Niwa Nagahide Akechi Mitsuhide Harada Naomasa † Araki Murashige Takayama Ukon Hosokawa Fujitaka Inaba Yoshimichi Andō Morinari Ikoma Chikamasa	Kōsa Shimozuma Nakayuki Shimozuma Rairyū Saika Magoichi Ashikaga Yoshiaki Rokkaku Yoshikata Mori Terumoto
Strength
at least 30,000	at least 15,000

The Ishiyama Hongan-ji War (石山合戦, Ishiyama Kassen) was a ten-year military campaign that took place from 1570 to 1580 in Sengoku period Japan, carried out by lord Oda Nobunaga against a network of fortifications, temples, and communities belonging to the Ikkō-ikki, a powerful faction of Jōdo Shinshū Buddhist monks and peasants opposed to the rule of the samurai class.

It centered on attempts to take down the Ikki's central base, the cathedral fortress of Ishiyama Hongan-ji, in what is today the city of Osaka. While Nobunaga and his allies led attacks on Ikki communities and fortifications in the nearby provinces, weakening the Hongan-ji's support structure, elements of his army remained camped outside the Hongan-ji, blocking supplies to the fortress and serving as scouts.