Lifespan: Tenbun 16 (1547) to 8/2 of Bunroku 2 (1593)
Other Names: Shiokikumaru (childhood)
Title: Junior Assistant Minister of Central Affairs
Lord: Ōtomo Yoshishige (Sōrin) → Ōtomo Yoshimune
Father: Wakabayashi Echigo-no-kami
Wife: [Formal] Daughter of Uragami Munekane
Children: Muneoki (Munemasa), Heiemon, Hanemon, Munemasa
Wakabayashi Shigeoki served as a bushō during the Sengoku and Azuchi-Momoyama periods. He was a retainer of the Ōtomo clan of Bungo Province in northern Kyūshū.
In 1547, Shigeoki was born as the son of Wakabayashi Echigo-no-kami. Originally, the Wakabayashi clan were a gōzoku, or wealthy family, from Shimotsuke Province but, began to serve the Ōtomo clan prior to the Muromachi period. The clan possessed landholdings in Isshakuya in the township of Saga-no-seki in Bungo. Owing in part to their location, the Wakabayashi served in the core of the naval forces of the Ōtomo clan.
In 1569, Mōri Motonari of Aki Province commenced an invasion of northern Kyūshū. Kokujin, or provincial landowners, including the Akizuki and Takahashi, opposed the governance of the Ōtomo and were lured through the devices of Motonari to betray them, so the front lines of the Ōtomo army in Buzen and Chikuzen provinces collapsed, triggering a major crisis for the clan. Ōtomo Yoshishige (also known as Ōtomo Sōrin, a sengoku daimyō and the twenty-first head of the Ōtomo) drew upon support from forces commanded by Ōuchi Teruhiro (the second son of Ōuchi Masahiro, the fourteenth head of the Ōuchi) and ordered Shigeoki to provide transport via sea lane to the base of the Ōuchi in Yamaguchi in Suō Province. While en route, Shigeoki’s navy encountered several vessels from the Mōri navy and routed them. Shigeoki himself took the head of an enemy commander. After landing at the Aio Inlet in Suō, he delivered Teruhiro.
Later, the Ōuchi forces were outnumbered when the Mōri army led by Kikkawa Motoharu and the nucleus of the Mōri navy came back whereupon Shigeoki either retreated after several skirmishes with the Mōri navy or, upon hearing the urgent news, abandoned the Ōuchi forces under Teruhiro and fled. The Ōuchi forces were decimated, but the Mōri army had to withdraw from northern Kyūshū so, strategically, the Revolt of Ōuchi Teruhiro was a major success. Prior to departing from Bungo, on 10/6, Teruhiro promised to grant Shigeoki a fief of 50 koku in Hagi-no-tsu in Nagato Province. After Teruhiro’s subsequent death in battle, however, the promise evaporated.
In 1572, Shigeoki invaded Iyo in an effort to aid the Tosa-Ichijō clan (with whom he had familial ties) during a precarious situation. Two years later, when Ichijō Kanesada went into exile in Bungo, and, in 1575, during the invasion of Tosa Province in which the Ichijō army suffered a major defeat at the Battle of Shimantogawa, Shigeoki served as a member of the Ōtomo navy. As a result of these expeditions to other provinces, in 1578, Shigeoki served meritoriously during an invasion of Hyūga, but, at the Battle of Mimikawa, the main division of the Ōtomo army lost to the Shimazu army, and were forced from an offensive posture to a defensive one.
In 1580, a senior retainer of the Ōtomo named Tabaru Chikatsura launched a rebellion. Commanding the Ōtomo navy, Shigeoki initiated a naval blockade of the Kunisaki Peninsula which was the territory of the Tahara clan. Owing in part to inclement weather, the Ōtomo navy successfully repelled an attack by the Mōri navy. That same year, however, witnessed the outbreak of a rebellion by Takita Shōtetsu and by others across the territory of the Ōtomo. In the midst of this instability, the Shimazu army marched north from southern Kyūshū to commence an invasion of Bungo in an event known as the Hōsatsu War. Shigeoki, together with his designated heir, Wakabayashi Munemasa, holed-up in Usuki Castle and avoided danger.
During the Bunroku-Keichō Campaign from 1592, Shigeoki served in the naval forces under the command of the Ōtomo clan. Owing to errors made during the campaign, on 5/1 of Bunroku 2 (1593), Ōtomo Yoshimune was removed from his position. On 8/2, he died in 二間津 at the port of call while traveling through the Hayasui Straits. He was forty-seven years old.