Tokugawa Ieyasu was a Japanese samurai and shogun, founder in 1603 of the Tokugawa dynasty and shogunate, although he actually ruled Japan from 1600 after the Battle of Sekigahara. Officially, his rule ended in 1605, but Tokugawa continued to exercise his power through the so-called "Cloistered rule", but retained his power until his death.
Something interesting about his "shadow ruling"
Despite his formal abdication in 1605 in favor of his son Hidetada, Ieyasu remained the real ruler of Japan from the position of "retired shogun" (ogosho) until his death. During this period he moved to Sumpu, from where he directed the construction of his castle in Edo.
The culmination of the first Edo period was in 1614-1615 when Osaka was besieged. At the time, Hideyori (Ieyasu's son) was living in Osaka Castle, with no apparent ambition to remove Tokugawa from power. However, Ieyasu, who well understands that after his death the heir will continue to be a real danger to his family, manages to find a formal pretext to attack him. Initially, the fighting was on the side of Toyotomi's military units, led by Hideyori, but Ieyasu managed to regain the initiative. His troops, personally led by Shogun Hidetada, managed to permanently surround Osaka Castle, which was captured at the end of 1615. Hideyori, his mother Yodojimi and his heir perform sepuku. Hideyori's wife, Senhime (Ieyasu's granddaughter), is saved. With this event, the Tokugawa clan finally conquered Japan and from that moment on can apply without any restrictions their views on the development of the country.