He was born at Mizugae Castle in Hizen, a son of Ryuzoji Chikaie; his mother was Keigin-ni. The Ryuzoji served the Shoni, constables of Hizen, but had grown strong under his great-grandfather Iekane and were increasingly at odds with their Shoni masters.
As a small boy he entered Horin-in, took vows and was named Engetsu. It was not unusual for a warrior's son to grow up in a temple, and he is thought to have learned reading, writing and Buddhist studies there. At this point no one expected him to lead the clan.
Through a plot by Baba Yorichika, a senior Shoni retainer, his grandfather Iezumi, his father Chikaie and many relatives lost their lives. His great-grandfather Iekane, then over ninety, fled to the Kamachi of Chikugo. Engetsu escaped harm because he was in the temple, but the clan faced a grave crisis.
With Kamachi help Iekane returned to Hizen, defeated Baba Yorichika and rebuilt the Ryuzoji, but soon died. By his will Engetsu left the temple, became a warrior again and inherited the Mizugae Ryuzoji house. The boy raised as a monk now carried the task of reviving the clan.
When Taneyoshi, head of the main Muranaka Ryuzoji house, died, the retainers backed him to inherit that house too, and he married Taneyoshi's widow. He thus came to lead the whole Ryuzoji clan, and soon received a character of his name from Ouchi Yoshitaka, calling himself Takatane and then Takanobu.
When his patron Ouchi Yoshitaka was overthrown by his retainer Sue Takafusa, some Ryuzoji vassals also turned against Takanobu, and he was driven out of Saga. As his great-grandfather had done, he took refuge with Kamachi Akimori in Chikugo and waited for a chance to return.
With Kamachi Akimori's help he raised troops, fought his way back into Hizen and retook his castle at Saga. He defeated the rebellious vassals and secured control of his house, and from here he began in earnest the campaigns to subdue the powers of Hizen one by one.
Takanobu attacked the Shoni, his former masters and the foes who had destroyed his kin, and cornered their head Shoni Fuyuhisa at Seifukuji Castle. Fuyuhisa met his end there, and the Shoni, a house dating from the Kamakura period, were destroyed. Aided by his brother-in-law Nabeshima Naoshige, the Ryuzoji secured eastern Hizen.
Otomo Sorin of Bungo sent a huge army that besieged Saga Castle. Many inside favored holding out, but on Nabeshima Naoshige's advice they launched a night attack and routed the force of Otomo Chikasada camped at Imayama. This victory against heavy odds spread the Ryuzoji name across Kyushu.
By this year he had subdued the Arima and Omura of southern Hizen and held almost all of the province. When the Otomo were crushed by the Shimazu at the Battle of Mimikawa in Hyuga, he took the chance to advance into Chikugo, Chikuzen and Higo, bringing much of northern Kyushu under his sway.
Takanobu passed the headship to his son Masaie and moved to Suko Castle, but kept real power. At this time he was so mighty he was called lord of five provinces and two islands. It is also said that he indulged in drink and pleasure and pushed away Naoshige, who reproached him.
Accusing him of dealing with the Shimazu, Takanobu lured Kamachi Shigenami, lord of Yanagawa Castle in Chikugo, to Saga and had him killed, destroying the Kamachi family. Shigenami was a son of Kamachi Akimori, who had once sheltered Takanobu. This harsh act angered the warriors of Chikugo, and some broke with the Ryuzoji.
When Arima Harunobu of the Shimabara Peninsula allied with the Shimazu and rebelled, Takanobu invaded with a large army. But at Okitanawate, a narrow path between marshes, he was defeated by Shimazu Iehisa and others and lost his life on the field at 55. From then on the Ryuzoji declined.
Ōuchi YoshitakaNabeshima NaoshigeShimazu YoshihisaŌmura SumitadaŌtomo Sōrin
Takigawa KazumasuHachisuka MasakatsuSakai TadatsuguAkechi MitsuhideUesugi KenshinŌtomo SōrinKikkawa MotoharuLuís Fróis
People of the Sengoku/Azuchi-Momoyama period ・ People by period
Based on facts found in textbooks and biographies. Uncertain points are marked as such.