He was born in Kiyosu, Owari, the second son of Ikeda Tsuneoki, a senior retainer of Oda Nobunaga, with the childhood name Koshin. His father Tsuneoki was Nobunaga's foster brother and a warrior Nobunaga deeply trusted. After coming of age he called himself Terumasa, written with a different character at first. From boyhood he served close to Nobunaga.
He was adopted by his maternal uncle Arao Yoshihisa and became lord of Kida Castle in Owari. With his father and elder brother Motosuke he served Nobunaga and joined battles in many places. Later, when Araki Murashige rebelled against Nobunaga, he camped in Settsu with his father, gaining experience as a warrior through this campaign.
In the attack on the Araki side's Hanakuma Castle, he personally struck down several enemy warriors. For this feat he received from Nobunaga a letter of commendation praising his service. This first major recognition as a teenage warrior became a stepping stone for his later rise.
Nobunaga was killed by Akechi Mitsuhide in the Honnō-ji Incident. His father Tsuneoki allied with Hashiba Hideyoshi, and they even agreed that Terumasa would become Hideyoshi's adopted son. That year, when Hideyoshi held Nobunaga's funeral at Daitokuji in Kyoto, Terumasa carried Nobunaga's coffin together with Hideyoshi's adopted son Hashiba Hidekatsu.
In the Battle of Komaki and Nagakute between Hideyoshi and Tokugawa Ieyasu, his father Tsuneoki and brother Motosuke, on Hideyoshi's side, were both killed. Terumasa became head of the family and lord of Ōgaki Castle in Mino. Later, after marrying Ieyasu's daughter, he is said to have summoned the Tokugawa retainer who had killed his father and asked how his father died.
Keeping the same 130,000 koku, he moved to Gifu Castle in Mino. Afterward he joined most of Hideyoshi's campaigns of unification, including those against Kii, against Sassa Narimasa, and in Kyushu. Hideyoshi granted him the surname Hashiba and the clan name Toyotomi, and he came to be treated almost as a member of the Toyotomi family.
For leading troops in the Odawara campaign and the settlement of Ōu, he was moved to Yoshida in Mikawa and given over 150,000 koku. Attached to the kampaku Toyotomi Hidetsugu, he guarded the home front during the invasions of Korea. Ordered to build large ships, transport rice for the army and work on Fushimi Castle, he gained experience in castle building.
Through Hideyoshi's mediation, he married Tokugawa Ieyasu's daughter Tokuhime. Tokuhime had been married to Hōjō Ujinao of Odawara but had returned home after the fall of the Hōjō. This marriage made Terumasa Ieyasu's son-in-law and laid the foundation for the Ikeda family's later prosperity.
After Hideyoshi died, he drew close to Ieyasu and acted with warriors who prized military merit, such as Fukushima Masanori and Katō Kiyomasa. When Maeda Toshiie died, he joined six other commanders in an attempt to attack Ishida Mitsunari, who ran the administration. The split among the Toyotomi vassals led to the great battle of the next year.
Before the Battle of Sekigahara, he captured Gifu Castle, held by Oda Hidenobu. He competed fiercely with Fukushima Masanori to be first inside, but it is said that, though he actually entered first, he readily yielded the honor and agreed that both had taken the castle together. In the main battle he held in check the Western Army's Mōri forces on Mount Nangū.
For his services he received 520,000 koku and moved to Himeji in Harima as the first lord of the Himeji domain. From this year he spent nine years extensively rebuilding Himeji Castle, creating its present form with a beautiful white complex of connected keeps. Himeji Castle later became a National Treasure and is registered as a World Heritage Site.
He suffered a stroke but recovered for a time and visited Sunpu and Edo. He became the first daimyō outside the Tokugawa family to be appointed councilor and was granted the Matsudaira surname, being called "Matsudaira, Councilor of Harima." With his family's domains together exceeding 900,000 koku, he was also called the "Shogun of the West."
His stroke recurred, and he ended his life at Himeji. An anecdote says that Toyotomi Hideyori's senior retainers, who had said Hideyori would be safe as long as Terumasa held Osaka in check, were deeply shaken to hear of his death. He is said to have been a quiet, generous man, and his eldest son Toshitaka succeeded him.
Akechi MitsuhideOda NobunagaMaeda ToshiieTokugawa IeyasuIshida MitsunariFukushima MasanoriKatō KiyomasaToyotomi Hideyori
Hosokawa GraciaKatō YoshiakiHosokawa TadaokiWilliam Adams (Miura Anjin)Ōtani YoshitsuguDate MasamuneSanada Yukimura (Nobushige)Tachibana Muneshige
People of the Sengoku/Azuchi-Momoyama period ・ People by period
Based on facts found in textbooks and biographies. Uncertain points are marked as such.