Aikido is a Japanese martial art developed in the by Morihei Ueshiba (also known as O-sensei) as a reflection of his martial studies, philosophy and spiritual beliefs.
O-sensei developed Aikido in the 1920’s and 1930’s as a synthesis of his lifetime of martial arts training, as well as an expression of his personal philosophy of harmony and reconciliation.
Aikido is the modern evolution of several Japanese Koryū(old-style martial arts) that date back to the days of the samurai in feudal Japan. This traditional origin is seen today in the dojo etiquette and courtesy practiced, as well as certain stances and weapons used.
O-sensei originally referred to his martial art as Aiki Būdo (loosely translated as “the warrior’s path of the harmonious spirit”), but was officially adopted as "Aikido" in 1942 when the Greater Japan Martial Virtue Society reorganized and centralized many of the Japanese martial arts.
Today, Aikido is found all over the world and has diverged into many different federations and styles. Similarly, aspects of Aikido can be found in some ryū (schools) of Karatē, as well as the Korean art of Hapkido.
While each modern Aikido dojo has its own interpretations and emphasis of the art, they all share techniques and philosophies learned from O-sensei, as well as a common virtue of concern for the well-being of the attacker.