Lifespan: Eishō 15 (1518) to 5/7 of Keichō 2 (1597)
Title: Governor of Satsuma
Clan: Minamoto-Mutō → Sanada → Yazawa
Lord: Sanada Yorimasa → Takeda Nobutora → Takeda Shingen → Sanada Yukitaka → Sanada Nobutsuna → Sanada Masayuki
Father: Sanada Yorimasa
Siblings: Sanada Tsunayoshi, Sanada Yukitaka, Yoritsuna, Tokida Takanaga, Kanbara Yukisada, Unno Yukikage, Hagiwara Tsunashige
Wife: [Formal] Daughter of Nei Seiun
Children: Yoriyasu, Yorikuni, daughter (wife of Unno Yukisada, the son of Unno Teruyuki)
Yazawa Yoritsuna served as a bushō during the Sengoku period.
Yoritsuna was born as the third son of Sanada Yorimasa. His common name was Gennosuke and he was the younger brother of Sanada Yukitaka (Yukitsuna). The Yazawa family were jizamurai, or local samurai, governing the Yazawa township bordering the Sanada township. As a member of the Suwa clan, the Yazawa were opposed to the Sanada family, but after, Yoritsuna was adopted by the clan, the confrontation between the families subsided.
While in his youth, Yoritsuna entered the priesthood and became a monk at the Kurama Temple in Kyōto. Before long, however, he returned to secular life in his hometown. Yoritsuna followed after his older brother, Yukitsuna, as a member of the senpōshū, a group in Shinano loyal to Takeda Harunobu (Shingen).
Meanwhile, in the fifth month of 1541, at the Battle of Unnotaira, Yoritsuna and Yukitsuna joined the Unno clan but were defeated. Through the assistance of the Suwa clan, Yoritsuna submitted to Takeda Nobutora. Around this time, he obeyed the Kai-Takeda family not as a retainer of the Sanada but rather as an independent small-scale landowner.
In 1551, Yoritsuna, with the support of Yukitsuna, attacked Arato Castle in the Sarashina District of Shinano. This succeeded in eliminating Yamada Kunimasa and Azuma Kiyotsuna who were members of the Murakami family.
In the ninth month of 1563, Yoritsuna followed Yukitsuna’s nephew and successor, Sanada Nobutsuna, and contributed to the capture of Iwabitsu Castle of Kōzuke Province. Thereafter, Yoritsuna served on the front lines in the pacification of the Agatsuma District by the Sanada family, including, on a temporary basis, as the chamberlain of Iwabitsu Castle.
In the third month just prior to the Battle of Nagashino, he donated land from within his township with a value of 10 kanmon to his family temple, the Ryōsen Temple in Yazawa.
In the fifth month of 1575, after the death of Nobutsuna at the Battle of Nagashino, Yoritsuna served his nephew, Sanada Masayuki, who inherited the headship of the Sanada family. Masayuki was frequently on duty in Kōfu, so Yoritsuna took the lead in governing the Agatsuma District and the invasion of the Numata territory. In the fifth month of 1580, he succeeded in capturing Numata Castle and, owing to his contributions, was appointed as the chamberlain of Numata Castle. Around this time, he changed his name to Yoritsuna, likely receiving one of the characters in his name from Takeda Katsuyori.
According to records of the Chiisagata District, the Sanada conducted land surveys in the district from 1578 to 1579.
In the third month of 1582, after the Takeda family was extinguished in the Conquest of Kōshū led by Oda Nobunaga, Yoritsuna became a senior retainer of the Sanada family operating as an independent power. Sanada Masayuki sent numerous letters to give orders to Yoritsuna. On 6/17 of Tenshō 11 (1583), Yoritsuna received 200 kanmon for the territory of Numata. Yoritsuna worked on the front lines against the Gohōjō clan.
In a letter dated 3/14 of Tenshō 13 (1585), he was awarded 1,000 kanmon in the Unno territory as recognition for his service as the chamberlain of Numata Castle. That same year, at the Battle of Ueda, Yoritsuna was subject to an invasion of Numata by Hōjō Ujikuni, the uncle of Hōjō Ujinao acting in concert with Tokugawa Ieyasu, but Yoritsuna repelled them.
There is a letter from 1585 jointly signed by Yoritsuna and his eldest son, Yazawa Yoriyasu, but there are almost no records of his whereabouts thereafter so, around this time, it is surmised that he was succeeded by his son.
Thereafter, the Yazawa stood at the highest rank among the band of retainers serving the Sanada family.
On 5/7 of Keichō 2 (1597), Yoritsuna died at the age of eighty.
During the Edo period, their descendants served in the role as the head of chief retainers for the domain until the Meiji period. The family attained a fief of 2,000 koku.