Kumabe Chikanaga was a kokujin, or provincial landowner, in Higo Province during the Sengoku period.  He was called the twenty-eighth head of the Kumabe clan but the details remain uncertain.  He was the lord of Nagano Castle in the Yamaga District of Higo.  After cooperating in the backing of Kikuchi Yoshitake (the twenty-sixth and final head of the Higo-Kikuchi clan) by the Ōtomo clan, the Kumabe were affiliated with the Ōtomo.  Following the retirement of his father, Kumabe Chikaie, in 1573, Chikanaga became a central figure in the band of retainers of the former Kikuchi clan under the command of the Ōtomo.  Similar to Kumabe Tadanao, he made donations to the Uchida-Hachiman Shrine.

Conflicts with the Akahoshi clan

In the era of Chikanaga, the northern portion of Higo was governed by former retainers of the Kikuchi including the Jō, the Akahoshi, and the Kumabe under the umbrella of the Ōtomo.  Among these kokujn, Chikanaga vied with Akahoshi Chikaie for power.  Territorial disputes further deepened the divide.  In 1559, Chikanaga defeated an invasion by Chikaie at the Battle of Awasegawa.  After retreating in defeat, the Akahoshi requested support from the Ōtomo so Chikanaga opposed their action by joining forces with Ryūzōji Takanobu of neighboring Hizen Province.  In the eleventh month of 1578, after the Ōtomo suffered a major defeat to the Shimazu clan at the Battle of Mimikawa, Chikanaga cooperated with the Ryūzōji clan during their invasion of Higo.

In the third month of 1580, Chikanaga and Jō Chikakata attacked the Aso clan (affiliated with the Ōtomo).  This attack, however, was repelled by Kai Chikanao (Sōun), a senior retainer of the Aso clan at Tankanose in Shirakawa.  At the end of the seventh month, Chikanaga joined with Ryūzōji forces led by Egami Ietane to attack Hoshiko Chūmu 廉正 (under the command of Akahoshi Muneie) at Nagasaka Castle.  These forces defeated reinforcements led by Kōshi Chikatame (the uncle of Akahoshi Muneie).  On 8/2, the besieging forces compelled 廉正 to take his own life and captured Nagasaka Castle, after which a retainer named Udō Kanemoto was appointed as the chamberlain.  In 1581, after Ryūzōji Masaie captured the base of the Akahoshi clan at Waifu Castle, Chikanaga was assigned command of the castle.

Around this time, he moved his main base from Nagano Castle to Waifu Castle and had his son, Kumabe Chikayasu, enter Jōmura Castle.  He had unspecified landholdings in Kikuchi, Yamaga, and Yamamoto and expanded his power by actively promoting marital relationships with former retainers of the Kikuchi clan.

In the third month of 1584, Ryūzōji Takanobu, an ally, was killed at the Battle of Okitanawate.  This led to a rapid decline in the influence of the Ryūzōji clan in Higo.  In the eighth month, the Shimazu clan invaded the northern portion of Higo and, in the ninth month, Chikanaga tendered a hostage and surrendered.

Uprisings by kunishū of Higo

After Toyotomi Hideyoshi commenced the Subjugation of Kyūshū in the third month of 1587, Chikanaga, along with other kokujin in Higo, submitted to Hideyoshi.  His landholdings, however, were significantly reduced.

In the sixth month of 1587, Sassa Narimasa became the landlord of the entire province of Higo and the kokujin were brought into the fold as yoriki, or security officers, under Narimasa.  When Narimasa attempted to conduct an intrusive land survey, Chikanaga asserted it was a violation of territorial rights and objected on the basis of the license issued by Hideyoshi.  In the seventh month, Chikanaga holed-up in Waifu Castle.  On 8/6, after Narimasa attacked with 6,000 troops, he abandoned Waifu Castle and entered Jōmura Castle.

Numerous kokujin responded by raising arms so Narimasa was unable to suppress the ikki forces (participants in the uprising) on his own and appealed to Hideyoshi for reinforcements.  Having established Kyūshū as a supply base for the planned invasion of the Korean Peninsula, Hideyoshi aimed to quickly quell the uprising by ordering a general mobilization of daimyō from Kyūshū and Shikoku to attack the ikki forces.  At the end of the year, upon the recommendation of Ankokuji Ekei, Chikanaga vacated Jōmura Castle and Tanaka Castle fell at the same time while the uprising was suppressed.  After surrendering, he was tendered to Tachibana Muneshige of Chikugo Province and sentenced to death via a duel among his close associates in front of the black gates of Yanagawa Castle.  Meanwhile, his son, Kumabe Chikayasu, was tendered to the Mōri clan and executed the next year in Kokura in Buzen Province.

Anecdotes

On 5/15 of Heisei 21 (2009), it was announced that the ruins of the residence of the Kumabe clan (Nagano Castle ruins) in the town of Kikuka in the city of Yamaga in Kumamoto Prefecture were a nationally designated historical site with the formal designation occurring in the seventh month.

To commemorate the designation, plans were made to build a copper statue of Kumabe Chikanaga in the city of Yamaga.  In 2010, work began at Anzu-no-oka in the town of Kikuka in the city of Yamaga and an unveiling ceremony was held on 11/26 of Heisei 23 (2011).  The statue is five meters tall and, together with its base, stands ten meters in height.  Along with the statue of Katō Kiyomasa at the Honmyō Temple, it is said to be the most prominent statue of a bushi in the prefecture.