Morihei Ueshiba developed Aikido from his experience in both traditional Japanese martial arts and modern warfare, resulting in a system of battle-tested principles designed specifically for the modern era.  Ueshiba, now referred to as O-Sensei (Great Teacher) by his students, offered his art not only as a means of defense against punches, kicks, knives, and guns, but also a study of unifying the mind, body and spirit.  Hence, O-Sensei chose to represent Aikido with symbols usually translated as "The Way of Harmony"; this focus on harmony entails the aiki strategy of blending with attacking force in order to neutralize it, as well as a grand strategy of neutralizing aggression through behavior and actions that discourage violence--even before it begins.

With Aikido, O-Sensei won the interest of great martial artists from Judo, Karate, and other styles, including Jigoro Kano, Gozo Shioda, Kenji Tomiki, and Minoru Mochizuki--all of whom endeavored to train with O-Sensei, some of them becoming his highest-ranking disciples.  These students went on to spread Aikido all over the world.

Because Aikido techniques redirect the force of attacks back onto the attacker, an Aikido practitioner needs only a minimum of strength, stamina or size.  Thus, Aikido can be performed by anyone--eight to eighty; weak, supple or strong.  However, benefits of Aikido training include increased stamina, flexibility, and strength, as its stretching and other physical exertions contribute to overall health.  For example, some of the most accomplished followers of O-Sensei did not begin training until their forties, yet they continue to teach, now in their eighties and nineties.  O-Sensei, himself, pursued a vigorous teaching and training schedule until only a few days before his death, at age eighty-five; in this way, Aikido fulfills the intentions of O-Sensei to both preserve life and improve its quality.