Before the term “bushido” (literally “the way of the warrior”) was ever invented, samurai warriors used the term “kyuba no michi” to describe their way of life. The meaning of this phrase is “the way of the bow and the horse,” reflecting the fact that the early samurai were elite mounted archers rather than swordsmen. Spearmen and musketeers came to dominate the Japanese battlefield, with the sword in a largely symbolic role as “the soul of the samurai.” But the early importance of the bow was never quite forgotten, and archery is still one of the surviving Japanese martial arts.
“Kyudo” or “the way of the bow” is a “budo” discipline, in other words a martial art practiced for purposes of self-cultivation. Contrary to popular opinion, though, it has no particular connection to Zen Buddhism. That notion was promulgated by a German man named Eugen Herrigel, who studied Kyudo briefly in Japan under a somewhat eccentric master of the art. Herrigel's master had actually founded his own religion, and his references to his personal religious concepts were not clearly understood by Herrigel, who wrongly assumed they referred to Zen.
Herrigel's book “Zen in the Art of Archery” was so popular in the West that its influence eventually spread back to Japan, leading to the creation of various “spiritual” Kyudo organizations, some of which then attracted many Western students because their combination of archery and spirituality fit those students' preconceptions perfectly. It's an odd case- Herrigel basically got it wrong, yet his mistake became reality over time!