Rusu Masakage

Rusu Masakage (1549-1607) was a senior retainer of the Date family and the uncle of Date Masamune. He assisted his elder brother Terumune and his nephew Date Masamune and contributed to the expansion of the power of the Date clan. While succeeding to the name of the Rusu clan, a famous family of Ōshū, he formed the core of the Date kinsmen.

Masakage was born as the third son of Date Harumune. In Eiroku 10 (1567), through the political scheming of his father Harumune, he was adopted by Rusu Akimune. He suppressed the rebellions of the Muraoka clan and the Amarume clan and fought across various regions. In Tenshō 18 (1590), he did not take part in Toyotomi Hideyoshi's Odawara campaign, and as a result his domains were confiscated in the Ōshū Shioki (Hideyoshi's settlement of the north). Afterward, he crossed the sea to Korea and took part in the Bunroku campaign in Korea. After returning home, he formally joined the kinsmen of the Date clan.

During the Battle of Sekigahara (1600), on Date Masamune's order, he served as commander-in-chief of the Date forces. He went to the relief of Mogami Yoshiaki, who was under attack by Uesugi Kagekatsu, and fought against the army of Naoe Kanetsugu as it withdrew (the Battle of Hasedō Castle). In Keichō 9 (1604), he was granted Ichinoseki with 20,000 koku. He died in 1607. His eldest son, Munetoshi, became the founder of the Mizusawa Date family, a kinsman house of the Sendai Domain.