Task: Text Categorization
Input (English): Toward the end of this period the office of Shikken assumed most of the Shoguns power, and Northern and Southern imperial lines existed simultaneously. It began when the Taira clan was defeated in the Gempei war, and also saw the defeat of two Mongol invasions. However, it ended when one of the generals in the Genko war defected to the emperor Go-Daigo. Seeing the rule of the Minimoto and Hojo families, For 10 points, identify this first Japanese Shogunate, which was succeeded by the Ashikaga Shogunate and is named for a city near Tokyo.
Output (English): History