Although the creation of Aikido is the work of one man, Morihei Ueshiba (1883-1969), Aikido is also the culmination of several traditional Japanese martial arts. Japanese sword, staff and spear techniques and jujutsu (particularly Daito-ryu jujutsu, in which he was taught by Sokaku Takeda) were part of his life-long commitment to budo.
However, he gradually developed what he had learned into an original art that integrated not only the various techniques but also the spiritual insights he had derived from his remarkable life experiences. He began using the term aiki, as in aiki-budo and later aikido to emphasize that his was an art of harmony, in which one would attempt to enter into and blend with the physical and spiritual energy of an attacker. Aiki signifies a relaxed, fluid and centered movement that is connected to, and guides, an attack even before contact is made. Not only would this approach bring an effective end to aggressive conflict, but would also allow the defender to purify their own aggressive impulses.
Because of this remarkable contribution, students of Aikido usually refer to Morihei Ueshiba as O Sensei, signifying the great esteem in which he is held.