Rusu Family Crest
Rusu Masakage and Four Martyrs
Lifespan: Tenbun 18 (1549) to 2/3 of Keichō 12 (1607)
Other Names: Date Masakage
Title: Junior Fifth Rank (Lower) and Governor of Kazusa
Clan: Date → Rusu
Lord: Date Terumune → Date Masamune
Father: Date Harumune
Mother: Kubohime (daughter of Iwaki Shigetaka)
Siblings: Iwaki Chikataka, Onamihime, Date Terumune, Kyōseiin, sister (wife of Koyanagawa Morimune), Masakage, Ishikawa Akimitsu, Hikohime, Hōjuin, Kokubun Morishige, Sugime Naomune
Wife: 竹乙 (daughter of Kurokawa Haruuji)
Children: Munetoshi, Tendō Shigeyori
Rusu Masakage served as a bushō from the Sengoku to early Edo periods. Masakage was a member of the Date family and served as the eighteenth head of the Rusu clan. He first resided in Iwakiri Castle and, later, in Rifu Castle in Mutsu Province.
In 1549, Masakage was born as the third son of Date Harumune. In 1567, for political reasons, his father arranged for the adoption of Masakage by Rusu Akimune, the lord of Iwakiri Castle in the Miyagi District of Mutsu. Masakage subsequently became the heir to the Rusu – a renowned clan in Mutsu. Later, he suppressed opposition by the Muraoka and Amarume clans. Masakage provided support to his older brother, Date Terumune, and nephew, Date Masamune, contributing to an expansion of the power wielded by the Date clan. Masakage participated in battles across the province.
In 1590, owing to his failure to serve in the Conquest of Odawara led by Toyotomi Hideyoshi, his landholdings were seized. On 7/26 of Tenshō 18 (1590), Kurokawa Haruuji (Masakage’s father-in-law) was also criticized for his absence from the Conquest of Odawara and was removed from his position as the lord of Tsurutate Castle. Hideyoshi had earlier recognized Masamune’s governance of the territory occupied by the Kurokawa. Owing to lingering bitterness of Masamune toward Haruuji in connection with the Battle of Ōsaki, Masamune aimed to kill Haruuji, but, following mediation by Masakage, Haruuji was spared. Thereafter, Haruuji spent the remainder of his life under the protection of Masakage.
In 1592, Masakage crossed to the Korean Peninsula to serve in the Bunroku Campaign. Upon his return to Japan, Masakage was formally recognized as a member of the Date clan.
In 1600, at the Battle of Sekigahara, upon orders of Masamune, Masakage headed out in support of Mogami Yoshiaki who was under attack by the forces of Uesugi Kagekatsu while serving as the commander-in-chief of the Date army. After arriving at the Koshira River, he clashed against the Uesugi army led by Naoe Kanetsugu who were in the midst of withdrawing. After the war, according to a letter from Masamune, Date forces took between 80 to 100 enemy heads while a family member named Ōe Saneyori was wounded during a violent battle known as the Siege of Hasedō Castle.
Later, Masamune permitted him to revert to the Date surname and, in 1604, he was granted a fief of 20,000 koku in Ichinoseki.
In 1607, Masakage died at the age of fifty-nine. The family temple was the Daian Temple in Mizusawa in Mutsu. At this temple is a rare portrait of Masakage along with four martyrs dated from Keichō 15 (1610) as depicted in this profile.
His eldest son, Rusu Munetoshi, later became the lord of Kanagasaki Castle located in Tsuruga in Echizen Province. He founded the Mizusawa-Date family, members of the Sendai domain.