Emperor Kammu was the 50th emperor of Japan, reigning from 781 to 806 AD. He is known for moving the capital from Nara to Kyoto, which became the center of Japanese culture and politics for centuries. His reign marked the beginning of the Heian period, a time of significant cultural development. Kammu focused on consolidating power and reducing the influence of powerful Buddhist temples. He implemented various administrative reforms to strengthen the imperial government. His efforts laid the groundwork for a more centralized state, influencing the future of the Japanese imperial system.