Ueshiba developed aikido primarily during the late 1920s through the 1930s through the synthesis of the older martial arts that he had studied. The core martial art from which aikido derives is Daitō-ryū aiki-jūjutsu, which Ueshiba studied directly with Takeda Sōkaku, the reviver of that art. Additionally, Ueshiba is known to have studied Tenjin Shin'yō-ryū with Tozawa Tokusaburō in Tokyo in 1901, Gotōha Yagyū Shingan-ryū under Nakai Masakatsu in Sakai from 1903 to 1908, and judo with Kiyoichi Takagi (高木 喜代子 Takagi Kiyoichi, 1894–1972) in Tanabe in 1911.

The art of Daitō-ryū is the primary technical influence on aikido. Along with empty-handed throwing and joint-locking techniques, Ueshiba incorporated training movements with weapons, such as those for the spear (yari), short staff (jō), and perhaps the bayonet (銃剣, jūken^?). However, aikido derives much of its technical structure from the art of swordsmanship (kenjutsu).

Ueshiba moved to Hokkaidō in 1912, and began studying under Takeda Sokaku in 1915. His official association with Daitō-ryū continued until 1937. However, during the latter part of that period, Ueshiba had already begun to distance himself from Takeda and the Daitō-ryū. At that time Ueshiba was referring to his martial art as "Aiki Budō". It is unclear exactly when Ueshiba began using the name "aikido", but it became the official name of the art in 1942 when the Greater Japan Martial Virtue Society (Dai Nippon Butoku Kai) was engaged in a government sponsored reorganization and centralization of Japanese martial arts.

The most unusual aspect of Aikido is that although it is primarily a self defence art, it takes the basic of its philosophy of being in harmony with the opponent rather than being in conflict. The idea is not to think of defeating the enemy but rather to be in harmony with him. That is why Aikido is sometimes called the art of non resistance or non fighting art.

As one learns the various techniques individuals will at the same time train their minds, improve health and develop confidence.

The movements of Aikido emphasise a flowing flexibility and the maintaining of a stable balance. The aim is to be in complete control of his or her mind and body. Much of the beauty of Aikido derives from the co-ordinated motion of the entire body with each movement of a part of the body contributing to the integrated sequence of movements.

Most of the joint techniques flex the joints in the direction of natural bending. They are in harmony with natural flexing and although painful to an attacker result in no permanent damage to the joint.

Aikido is a method of self defence which can be used against any form of attack. There is no attack in Aikido, the goal is merely to neutralize any aggression and can be practised by all ages and both sexes.