The classic depiction of the destruction of a clan, immortalized in history, fiction, and folklore, comes at the end of the Genpei War (1180-1185).  In a naval battle at the Straits of Shimonoseki, the Minamoto clan wiped out the Imperial Taira, ushering in the supremacy of the samurai.

For the next 650 years (aside from the brief resurgence of the Southern Imperial Court), emperors reigned but did not rule (they really didn't rule after 1868 either). The head of state was the shogun ("generalissimo"), though he was more the hereditary prime minister in a one-party state.

With the Osaka Campaigns (which destroyed the Toyotomi clan, the one remaining threat to Tokugawa rule) and the Shimabara Rebellion over by 1638, there wasn't any generalling left to do, which left the shogunate woefully unprepared when Admiral Perry showed up in 1853.

Labels: 12 kingdoms, history, japan, poseidon