The Second Siege of Kuroi Castle occurred from 7/1 to 8/9 of Tenshō 7 (1579) at Kuroi Castle in the Hikami District of Tanba Province.  During the Azuchi-Momoyama period, Akechi Mitsuhide acted upon orders of Oda Nobunaga to conquer Tanba Province triggering a battle for the base of the Akai clan – the stronghold of Kuroi Castle.  These assaults on the castle occurred twice, with the First Siege of Kuroi Castle in 1575 and the Second Siege of Kuroi Castle in 1579.

Prelude

In the first month of 1577, Mitsuhide commenced the construction of Kameyama Castle in the Kuwada District of Tanba to serve as a base for the invasion of Tanba.  Upon the end of the Siege of Shigisan Castle in the tenth month, Mitsuhide commenced the second invasion of Tanba.  Initially, in the Taki District, the Akechi forces toppled Momii and Hadakasa castles in addition to eleven outlying castles.  Mitsuhide wrote a letter stating that, owing to this invasion, the only castles remaining to be captured were those held by the Araki and Hatano clans.  On 3/4 of Tenshō 6 (1578), Nobunaga ordered Hosokawa Fujitaka (Yūsai) to prepare the roads to the Taki and interior districts for the deployment by Nobunaga himself to Tanba.  On 4/10, Mitsuhide, together with Takigawa Kazumasu and Niwa Nagahide, toppled the base of Araki Ujitsuna at Araki Castle.

On 3/9, Ogino Naomasa died of illness.  According to one theory, he suffered from an illness of carbuncles.  Perhaps owing to the death of Naomasa, from this year forward, the Akai clan made clear their alliance with the Hatano clan and resumed fighting against Mitsuhide.  In the second month of 1578, Mitsuhide was dispatched to Harima to respond to a defection by Bessho Nagaharu.  This is known as the Siege of Miki.  From the ninth month, he launched an assault against Yakami Castle held by the Hatano clan.  He built Kinzan Castle on the border of the Taki and Hikami districts, aiming to block coordination between the Hatano and Akai clans.  In parallel, he responded to the revolt by Araki Murashige at Arioka Castle in Itami.  This is known as the Siege of Arioka Castle.  In the twelfth month, Mitsuhide headed toward Yakami Castle where he delegated an assault to Kobatake Nagaaki and other kunishū from Tanba.  He reinforced the siege of the castle which began from around the ninth month and completely severed the provisioning of the castle.  On 5/5 of Tenshō 7 (1579), Hikami Castle (an auxiliary site for Yakami Castle) was toppled and, on 6/1, Yakami Castle was vacated along with the surrender of the Hatano siblings.

Hatano Hideharu, Hatano Hidenao, and Hatano Hidetaka were apprehended and, after being paraded around Kyōto, were transported to Azuchi and, upon orders of Nobunaga, crucified.  In the seventh month, Mitsuhide (who had been on deployment in Yamato Province during the latter half of the sixth month) entered Tanba again and joined the assault on Kuroi Castle.

Course of events

Unlike during the First Siege of Kuroi Castle, the army led by Akai Tadaie did not receive reinforcements from the Hatano family while many of the outlying castles around Kuroi Castle were toppled and the military power of the defenders is surmised to have dropped significantly.

The battle began on the early morning of 8/9.  Mitsuhide leveraged his learnings from the defeat in the first siege, proceeding prudently.  He set fires at illusory bases and blew on conches to stir-up chaos.  He feigned assaults and then pulled back, launching pincer attacks against members of the castle garrison lured to pursue them while the besieging forces attacked repeatedly from all directions.  In the midst of this guerilla warfare, the battalion of Shiōten Masataka of the Akechi army toppled the Senjōji fortress when the defenders were shorthanded and commenced an all-out attack against the main walls of the castle.  Owing to the strategy of the Akechi army to draw-out the enemy forces, there were few forces remaining to guard the castle walls, and despite valiant fighting by Akai Tadaie, but in the end, he set fire to the castle and fled in defeat.  While on the verge of total annihilation, this was avoided perhaps because each side regretted further losses or had suitable mediators.  During the battle, residents within a limited area fought against one another and there were also cases of persons to mediate based on locale or family relationships.

Victory letter

A letter dated 8/24 of Tenshō 7 (1579), fifteen days after the fall of Kuroi Castle, was sent to the Itoku Temple in Kyōto where Mitsuhide earlier prayed for victory.  The letter states that victory was achieved so, as promised, 200 koku would be donated to the temple.  Soon thereafter, Takami Castle deemed to have been the base of Akai Tadaie fell and, over the next few days, the army advanced in the direction of Wada.  Letters shed light on the earnest character of Mitsuhide who placed a value on his religious beliefs.  After minor skirmishes with a limited opposition, Mitsuhide resolved matters.  On 10/24, Mitsuhide and Fujitaka led a victorious army back to Azuchi Castle to meet with Nobunaga and report to him the details of the pacification of Tanba.  In 1580, Nobunaga awarded Tanba to Mitsuhide and Tango to Fujitaka.