Mori Tadamasa (森忠政)

Tadamasa MORI (1570 - July 31, 1634) is a military commander of the Warring States period in Japan. He was a daimyo of the early Edo period too. He was the lord of Kawanakajima domain in Shinano Province (Nagano Prefecture) and later the first lord of Tsuyama domain in Mimasaka Province (the northern part of Okayama Prefecture). He was the first family head of the Mori family of Ako Domain.

Family Line

His original surname was Genji (Minamoto clan). He was descended from Kawachi-Genji (Minamoto clan in Kawachi Province (south eastern part of Osaka Prefecture)) which was a branch family line of Seiwa-Genji (Minamoto clan originated in Emperor Seiwa).
His ancestor was Yorisada MORI who was the great grandson of MINAMOTO no Yoshiie
See the part of the Mori clan for more details.


In 1582, Tadamasa started to work under Nobunaga ODA as a page but was dismissed and sent back to his mother by Nobunaga; Nobunaga thought, upon finding Tadamasa in a fight with one of his colleagues, that he was too young to do the job. The dismissal turned to be a lucky incident for Tadamasa because it prevented him from being involved in the Raid on the Honno-ji Temple (in which Nobunaga ODA was killed).

One of his elder brothers Nagayoshi was killed in the Battle of Komaki and Nagakute in 1584, and later Tadamasa succeeded to the Mori estate as his other elder brothers had died earlier as well. He held a fief of 70,000 koku of rice in Mino Province (southern Gifu Prefecture) making his home at Kaneyama-jo Castle. In 1587, he was given the surname of Hashiba from Hideyoshi TOYOTOMI and called himself Hashiba Kaneyama Jiju (chamberlain).

At the time of Hideyoshi's invasions of Korea, Tadamasa joined the camp at Nagoya-jo Castle in Kyushu as a fushin bugyo (public work administrator) leading 2,000 soldiers.
(But he did not cross the sea.)

After the death of Hideyoshi, Tadamasa approached Ieyasu TOKUGAWA, from whom he was awarded Matsushiro Domain, a fief of 137,000 koku of rice, in Shinano Province (Nagano Prefecture) in 1600. Tadamasa joined up with the eastern army of Hidetada TOKUGAWA in the Battle of Sekigahara of the same year, and participated in the attacks against Ueda-jo Castle which was the base for Masayuki SANADA of the western army. On this occasion he resumed his surname of Mori from Hashiba which had been given by Hideyoshi. After the Battle of Sekigahara he was given a fief of 180,000 koku of rice in Tsuyama for his distinguished military services, and became the first lord of Tsuyama Domain. Tadamasa died in 1634. It is said that he got a stomachache after eating a peach and died without recovering from it - the cause of his death being explained as food poisoning. He was entombed in Sangen-in of Daitoku-ji Subtemple at Kyoto Murasakino (which is also a family temple of Mitsunari ISHIDA). His kaimyo (posthumous Buddhist name) is 本源院殿前作州太守先翁宗進大居士.

Record of offices and ranks held

Date: old lunar calendar

October 6, 1585: appointed Jugoinoge ukon no jo (Ukon no jo of Junior Fifth Rank, Lower Grade)

February 6, 1587: Jushiinoge jiju (Junior Fourth Rank, Lower Grade Chamberlain)
From this time on he called himself 'Ukon no taifu (Lieutenant of the Right Division of Inner Palace Guards) Tadamasa'.

August 19, 1626: Jushiiinoge (Junior Fourth Rank Upper Grade) Sakone gon no chujo (Provisional Middle Captain of the Left Division of Inner Palace Guards)