Siege of Tanabe Castle
Date: 7/19 to 9/6 of Keichō 5 (1600)
Location: Tanabe Castle in the Kasa District of Tango Province
Synopsis: While Hosokawa Tadaoki, the lord of Tanabe Castle, was away on an expedition, his father and brother defended the castle with a garrison of 500 soldiers against a besieging army of 15,000 men. The attacks were halted upon imperial orders from Emperor Goyōzei to protect Hosokawa Yūsai, a renowned cultural figure and master of classical poetry defending the castle. Although the defenders finally vacated the castle, the besieging forces missed the main Battle of Sekigahara in which the Eastern Army prevailed, turning it into a nominal victory for the Western Army.
The Siege of Tanabe Castle occurred from 7/19 to 9/6 of Keichō 5 (1600) in a contest for control of Tanabe Castle in the Kasa District of Tango Province. The conflict was triggered when Onogi Shigekatsu (the lord of Fukuchiyama Castle in the Amata District of Tanba) and Maeda Shigekatsu (the lord of Kameyama Castle in the Kuwada District of Tanba) of the Western Army attacked Tanabe Castle defended by Hosokawa Yūsai and Hosokawa Yukitaka of the Eastern Army. This siege was a preliminary contest under a broad definition to the Battle of Sekigahara and, although the defenders ultimately vacated the castle, the army laying siege was unable to arrive in time for the main Battle of Sekigahara in which the Western Army was defeated by Tokugawa Ieyasu and allied forces.
Toward the end of the Toyotomi administration, Tokugawa Ieyasu served as the head of the Council of Five Elders. Prior to his death in 1598, Toyotomi Hideyoshi requested that Ieyasu, along with Mōri Terumoto, Uesugi Kagekatsu, Maeda Toshiie, and Ukita Hideie (in addition to Ishida Mitsunari as a sixth member), manage the affairs of the Toyotomi administration through this parliamentary body until Hideyoshi’s eldest son and heir, Toyotomi Hideyori, reached adulthood and could lead the administration. As the most senior member of the Council, Ieyasu requested Uesugi Kagekatsu to visit Kyōto as an expression of his intent to comply with the new order, but Kagekatsu refused and instead adopted an increasingly defiant posture. In the sixth month of 1600, Ieyasu assembled an army for an expedition aimed at subduing Kagekatsu at his base in Aizu in Mutsu Province, an event known as the Conquest of Aizu.
Meanwhile, Ishida Mitsunari, who was confined to Sawayama in the Sakata District of Ōmi Province, also opposed Ieyasu. Following the deployment by Ieyasu and his army for the Conquest of Aizu, Mitsunari took advantage of the military vacuum this created in the Kinai whereupon he entered Ōsaka Castle and raised arms in opposition to Ieyasu.
Under the direction of Mitsunari, the Western Army first focused on suppressing the allies of Ieyasu in the provinces neighboring the Kinai. Tanabe Castle in Tango, the base of Hosokawa Tadaoki who was absent while participating in the eastward march to subdue Uesugi Kagekatsu, became one of the targets. Commanders from Tanba and Tajima provinces including Onogi Shigekatsu, Maeda Shigekatsu, Oda Nobukane, Koide Yoshimasa, Sugihara Nagafusa, Tani Moritomo, Fujikake Nagakatsu, Kawakatsu Hideuji, Hayakawa Nagamasa, Hasegawa Sōnin, Saimura Masahiro, and Yamana Tonomo-no-kami led an army of 15,000 soldiers to lay siege to the castle.
Tadaoki had taken most of his forces with him from Tango, leaving Tanabe Castle to be defended by his younger brother (Hosokawa Yukitaka), his father (Hosokawa Yūsai), and his cousin (Mitsubuchi Mitsuyuki – Yūsai’s nephew) commanding a garrison of only 500 soldiers. Yukitaka and Yūsai resisted, but the imbalance in forces became more attenuated, while there was no prospect for the arrival of reinforcements. In fighting that began from 7/19, the castle was on the brink of falling by the end of the same month.
Among the besieging army, however, were numerous disciples of Yūsai in the literary arts and tea ceremony. These men revered Yūsai as a master and preeminent authority in cultural arts of his era, dampening their enthusiasm to attack. Yūsai had inherited from Sanjōnishi Saneeda the kokin-denju, a collection of interpretations ofｗaka, or classical Japanese poetry, that were secretly communicated for generations by masters to their disciples to convey the essence of these writings. Disciples of Yūsai including Hachijōnomiya Toshihito-shinnō, in addition to his older brother, Emperor Goyōzei, feared the potential killing of Yūsai and loss of the kokin-denju. On two occasions, in the seventh and eighth months, Hachijōnomiya sent a messenger to advise the defenders to vacate the castle but Yūsai refused, informed the messenger of his will to fight to the end, and continued to defend the castle. He gave a certificate evidencing the kokin compilation to Hachijōnomiya and a collection of twenty-one waka to the Imperial Court.
Finally, the emperor dispatched as imperial messengers high-ranking nobles (who were also disciples of Yūsai in the cultural arts) including Sanjōnishi Saneeda (the Chief Councilor of State), Nakanoin Michikatsu (Vice Councilor of State), and Karasumaru Mitsuhiro (Lieutenant General), to visit both the Eastern and Western armies at Tanabe Castle and order a settlement. As an imperial order, Yūsai and Yukitaka were obliged to comply and, on 9/18, vacated Tanabe Castle and were taken to the base of the enemy commander (Maeda Shigekatsu) at Kameyama Castle in Tanba Province.
The Western army prevailed in this battle, but 15,000 soldiers from Tanba and Tajima, including Onogi Shigekatsu and other commanders, were pinned down at Tanabe Castle for the duration of the siege. This prevented these forces from participating in the main Battle of Sekigahara that occurred just two days after surrender of the castle, resulting in nationwide defeat for the Western Army.
There is a diary written by Mitoya Takakazu who entered Tanabe Castle on 7/15 that describes his observations and provides a detailed view into the happenings in the castle and the circumstances of an ordinary bushō during that period.