First go to What Is Yabusame? and learn about mounted archery. Then you can try it yourself in Virtual Yabusame. The page on Japanese Archery (Kyudo) tells you about the history of the sport that forms the core of yabusame. Kyudo itself is still practiced by many people, and you can read about this aspect at Kyudo as a Competitive Sport.
Photo courtesy of Tsurugaoka Hachiman Shrine