The Siege of Osaka was a series of battles undertaken by the Tokugawa shogunate against the Toyotomi clan; ending in that clan's destruction. Divided into two stages (Winter Campaign and Summer Campaign); and lasting from 1614 to 1615; the siege put an end to the last major armed opposition to the shogunate's establishment. The end of the conflict is sometimes called the Genna Armistice (Genna Enbu); because the era name was changed from Keicho to Genna immediately following the siege.