Ikeda Tomomasa was a kokujin and military commander in the Azuchi-Momoyama period

Azuchi-Momoyama period

The came at the end of the Warring States Period in Japan, when the political unification that preceded the establishment of the Tokugawa shogunate took place. It spans the years from approximately 1573 to 1603, during which time Oda Nobunaga and his successor, Toyotomi Hideyoshi, imposed order...

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He was the second son of Ikeda Nagamasa

Ikeda Nagamasa

Ikeda Nagamasa was a kokujin and samurai commander in the Sengoku period.Ikeda Katsumasa and Ikeda Tomomasa were his sons.His father was Ikeda Nobumasa and his mother was Miyoshi Masanaga's daughter....

, who was a dominant kokujin in Settsu Province

Settsu Province

was a province of Japan, which today comprises the eastern part of Hyōgo Prefecture and the northern part of Osaka Prefecture. It was also referred to as or .Osaka and Osaka Castle were the main center of the province.-History:...

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His older brother was Ikeda Katsumasa

Ikeda Katsumasa

was a daimyo in Japan's Azuchi-Momoyama period.His father was Ikeda Nagamasa and his young brother was Ikeda Tomomasa.In 1563, Katsumasa succeeded to a house when his father, Nagamasa died.These days Ikeda clan had belonged to Miyoshi clan....

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In 1568, when Oda Nobunaga

Oda Nobunaga

was the initiator of the unification of Japan under the shogunate in the late 16th century, which ruled Japan until the Meiji Restoration in 1868. He was also a major daimyo during the Sengoku period of Japanese history. His opus was continued, completed and finalized by his successors Toyotomi...

 marched his armies, Tomomasa and Katsumasa under Miyoshi clan

Miyoshi clan

The Miyoshi clan is a Japanese family descended from Emperor Seiwa and the Minamoto clan . They were a cadet branch of the Ogasawara clan and the Takeda clan....

 battled against him.
However, they were not equal to him by their nature.
They surrendered and served Nobunaga.
In 1570, when Ikeda clan

Ikeda clan

The was a Japanese clan that claimed descent from the Seiwa Genji. In the Edo period, several of the clan's branches were daimyo families, most notably of the Tottori Domain, and Okayama Domain. Takamasa Ikeda, present head of the Okayama Ikeda house is a husband of Atsuko Ikeda, fourth daughter...

's infighting happened, Katsumasa who was the family head was purged.
Because of that, Tomomasa succeeded to a house.
In 1571, he held secret communication with Miyoshi Nagayasu, Miyoshi Masayasu and Iwanari Tomomichi

Iwanari Tomomichi

was a Japanese samurai of the 16th century. Also known as Ishinari Tomomichi , he was a retainer of the Miyoshi clan, and held the title of Chikara-no-suke...

, and betrayed Nobunaga.
They defeated Wada Koremasa

Wada Koremasa

was a retainer beneath the clan of Oda throughout the latter Sengoku Period of Feudal Japan. Koremasa was the son of Wada Koresuke and directly supported the Ashikaga Shogunate by the time at which he was of eligible age, becoming a primary supporter to Ashikaga Yoshiaki following the murder of...

 and killed him.

However, Tomomasa surrendered again after Nobunaga ruled Settsu Province completely.
He became a retainer of Araki Murashige

Araki Murashige

was a retainer of Oda Nobunaga, and daimyō of Itami Castle during the late Sengoku period of the 16th century in Japanese history, in what is now Itami city in Hyōgo Prefecture....

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In 1580, he served Hashiba Hideyoshi

Toyotomi Hideyoshi

was a daimyo warrior, general and politician of the Sengoku period. He unified the political factions of Japan. He succeeded his former liege lord, Oda Nobunaga, and brought an end to the Sengoku period. The period of his rule is often called the Momoyama period, named after Hideyoshi's castle...

 after Murashige betrayed Nobunaga and was defeated.
Tomomasa under Hideyoshi took part in the Battle of Komaki and Nagakute

Battle of Komaki and Nagakute

The consisted of two battles in 1584 between the forces of Hashiba Hideyoshi and the forces of Oda Nobukatsu and Tokugawa Ieyasu. Hideyoshi and Ieyasu had both served Oda Nobunaga and had not previously come into conflict; this would in fact be their only period of enmity...

 and the expedition to Kyūshū

Kyushu Campaign

The Kyūshū Campaign of 1586-1587 was part of the campaigns of Toyotomi Hideyoshi who sought to dominate Japan at the end of the Sengoku period...

 (in 1586).

He served Tokugawa Ieyasu

Tokugawa Ieyasu

 was the founder and first shogun of the Tokugawa shogunate of Japan , which ruled from the Battle of Sekigahara  in 1600 until the Meiji Restoration in 1868. Ieyasu seized power in 1600, received appointment as shogun in 1603, abdicated from office in 1605, but...

 and was given 5,000 koku

Koku

The is a Japanese unit of volume, equal to ten cubic shaku. In this definition, 3.5937 koku equal one cubic metre, i.e. 1 koku is approximately 278.3 litres. The koku was originally defined as a quantity of rice, historically defined as enough rice to feed one person for one year...

 after Hideyoshi died.
After Tomomasa died, his son, Ikeda Shigenobu succeeded to a house.
However, his domain was seized by the shogunate

Tokugawa shogunate

The Tokugawa shogunate, also known as the and the , was a feudal regime of Japan established by Tokugawa Ieyasu and ruled by the shoguns of the Tokugawa family. This period is known as the Edo period and gets its name from the capital city, Edo, which is now called Tokyo, after the name was...

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