Lifespan: Eiroku 9 (1566) to Manji 3 (1660)
Other Names: Tarō (childhood), Chikayoshi, Shōzaemon-no-jō, Kozaemon-no-jō (common), 今楠木, Tenshō-no-kusunoki, Don Paulo (baptismal)
Lord: Ōtomo Yoshishige (Sōrin) → Ōtomo Yoshimune → Hachisuka Iemasa → Fukushima Masanori → Kobayakawa Hideaki → Fukushima Masanori → Mōri Terumoto
Father: Shiga Chikamori
Adoptive Father: Shiga Chikanori
Adoptive Mother: Daughter of Ōtomo Yoshishige (or the daughter of Nada-fujin and her prior husband, Hattori Ukyō-no-suke)
Wife: Daughter of Takita Shigechika (niece of Ōtomo Sōrin)
Children: Unknown (died early), Chikakatsu, daughter (died early)
Shiga Chikatsugu served as a bushō during the Azuchi-Momoyama period. Chikatsugu was a retainer of the Ōtomo clan and served as the lord of Oka Castle in Bungo Province.
Chikatsugu excelled in the military arts. His adoptive mother was the daughter of Ōtomo Sōrin, a sengoku daimyō and the twenty-first head of the Ōtomo clan. As a result, Chikatsugu was heavily relied upon by Sōrin.
In the seventh month of 1584, Chikatsugu participated in an attack against Nekoo Castle in the Kamitsuma District of Chikogo Province. The castle was defended by Kuroki Ienaga, a former retainer of the Ōtomo who had switched his allegiance to the Ryūzōji clan. In the ninth month, after his older brother (and adoptive father) Chikanori, had a falling out with Ōtomo Yoshimune and was demoted, Chikatsugu, at the age of nineteen, was ordered to succeed Chikanori as the head of the Shiga clan. In 1585, he converted to Christianity and received the baptismal name of Don Paulo.
Chikatsugu joined in the defense of Takamori Castle in the Aso District of Higo Province, repelling the Shimazu army. At the Siege of Oka Castle (located in the Naoiri District of Bungo), even after the retreat of Shimazu Yoshihiro, the commander-in-chief of the Shimazu army, Chikatsugu remained in place to defend against repeated assaults on the castle, sending the Shimazu fleeing in defeat.
In 1586, the Shimazu army comprised of 37,000 soldiers invaded Bungo, triggering the Hōsatsu War. Chikatsugu’s adoptive father, Shiga Chikanori, along with members of the Nangun group (southern districts of Bungo), allied with the Shimazu. To defend against the invaders, Chikatsugu holed-up along with 1,500 men at his base at Oka Castle. WIth a small garrison, the defenders repelled numerous assaults by the imposing Shimazu army led by Shimazu Yoshihiro and Niiro Tadamoto. In a final showdown at Oniga Castle, Chikatsugu, leading a force of 500 soldiers, thoroughly trounced Yoshihiro and an army of several thousand soldiers. In the course of this victory, the Shiga army incurred only twenty casualties. After reinforcements led by Toyotomi Hidenaga landed in Bungo, Chikatsugu decimated rebels among those from the Nangun group and had his father take his own life by the sword. Thereafter, he rescued five bushō from Shimabara who had been incarcerated at Ichimanda Castle. Bringing the Christian religion back home, this served as the roots of converts known as the kakure Christians, or hidden Christians, who worshiped underground to avoid persecution. In his command of these battles, Chikatsugu was lavishly praised by Toyotomi Hideyoshi for his exemplary service.
Later, under the guardianship of his grandfather, Shiga Chikamori, Chikatsugu transferred Oka Castle to the Nakagawa family and was granted by Hideyoshi landholdings of 1,000 koku in Hita. After the Ōtomo lost many retainers owing to the invasion by the Shimazu, Chikatsugu gained authority in the clan based on his notoriety for valor on the battlefield along with his well-known family name. Nevertheless, this led to alienation from his lord, Ōtomo Yoshimune. In the wake of Sōrin’s death, the practice of Christianity was banned, but Chikatsugu refused to abandon the religion and became a protector of Christian followers residing in Bungo. While Chikatsugu accompanied Ōtomo Yoshinori (Yoshimune’s lineal heir) on a visit to Ōsaka, Yoshimune expelled the missionaries from Bungo.
In 1592, while serving in the Bunroku Campaign, Chikatsugu believed a false report so while the Konishi battalion struggled he misread the situation on the battlefield and recommended to Yoshimune that the forces retreat. Viewed as fleeing in the face of the enemy, these actions upset Hideyoshi whereupon the Ōtomo were removed from their position and Chikatsugu lost his landholdings.
In the chronicles of Luís Fróis, a Jesuit missionary from Portugal who resided in Japan during the Sengoku period, it is only noted that, at this time, Chikatsugu went to Kyōto to seek a new position.
Thereafter, Chikatsugu served Hachisuka Iemasa and possessed 1,000 koku in the Ōi manor in the Hita District. In 1600, during the prelude to the Battle of Sekigahara, Chikatsugu supported Yoshimune in the Battle of Ishigakibaru. Next, he served Fukushima Masanori, then Kobayakawa Hideaki (for a stipend of 950 koku), and then returned to the service of Masanori, followed by Mōri Terumoto. He died at the age of ninety-five. Records of his grandfather, Chikamori, also exist over an extended period, suggesting his lineage was blessed with long lives.
Some of his descendants returned to Kyūshū and served the Hosokawa clan as retainers of the Kumamoto domain until the Meiji period. Chikatsugu’s grave is in Ono in the city of Ube in Yamaguchi Prefecture and his descendants continue to reside there.