Minamoto no Sanetomo

Minamoto no Sanetomo (1192 –1219, reigned 1203–1219) was the third Minamoto shogun of the Kamakura Period.  He was the second son of Minamoto no Yoritomo and Hōjō Masako and the younger brother of Yoriie (the second Minamoto shogun).

Following Yoritomo’s death in 1199, Yoriie became head of the Minamoto and a few years later, became shogun. Yoriie’s reign did not last long. Shortly after his appointment, he was stripped of political power by Hōjō Tokimasa, the father of Masako and grandfather of Yoriie and Sanetomo. After Yoriie was accused of plotting to usurp Hōjō Tokimasa, he was banished then assassinated.

Following Yoriie’s removal, Sanetomo was appointed shogun. Living with the constant fear of assassination Sanetomo devoted his time to acquiring court rank, writing poetry, and consuming alcohol. He achieved the lofty of Minister of the Right (Udaijin) by the Imperial Court. Sanetomo wrote some 700 waka poems, developing a reputation as a good poet. Eisai, spiritual advisor to Masako, attempted to cure his alcohol addiction by using green tea. However, his fears came true. While leaving a celebration ceremony of his appointment as udaijin, in a heavy snow, he was assassinated by his nephew Kugyō, the son of Yoriie.

Kugyō was immediately executed and thus ended the line of the Seiwa Genji of the Minamoto clan and their rule in the Kamakura Period.

Hōjō Masako and her father, Tokimasa, had been engaged in a power struggle. With the elevation of Sanetomo as shogun, Masako defeated Tokimasa, who shave his head and took tonsure in a Buddhist monastery. After the assassination of Sanetomo, Masako adopted the infant, Kujō Yoritsune, known as Fujiwara no Yoritsune, and he was named shogun. Thus Masako, being the infant’s mother, effectively became shogun until her death.