The Summer Siege of Osaka took place in 1615 during the Sengoku period in Japan. It was part of the larger conflict between the Tokugawa shogunate and the Toyotomi clan, which sought to regain power after the Winter Siege earlier that year. The siege aimed to eliminate the Toyotomi stronghold in Osaka Castle, which was held by Toyotomi Hideyori, the last heir of the clan. The Tokugawa forces, led by Tokugawa Ieyasu, launched a full-scale attack on the castle. After several months of intense fighting, the castle fell in September 1615. This defeat marked the end of the Toyotomi clan's influence and solidified the Tokugawa shogunate's control over Japan, leading to a long period of peace known as the Edo period.