Aikido was created by Morihei Ueshiba (植芝 盛平 Ueshiba Morihei. 14 December 1883 - 26 April 1969), referred to by his students as ŌSensei ("Great Teacher"). ŌSensei envisioned aikido not only as the synthesis of his martial training, but also an expression of his personal philosophy of universal peace and reconciliation. During ŌSensei's lifetime and continuing today, aikido has evolved fro the koryu (old-style martial arts) that ŌSensei studied into a wide variety of expressions by martial artists throughout the world.
Aikido is performed by blending with the motion of the attacker and redirecting the force of the attack rather than opposing it head-on. This requires very little physical energy, as the aikidoka (aikido practitioner) "leads" the attacker's momentum using entering and turning movements. The techniques are completed with various throws or joint locks. Aikido can be categorized under the general umbrella of grappling arts.
Aikido derives mainly from the martial art of Daitō-ryū aiki-jūjutsu, but began to diverge from it in the late 1920s, partly due to ŌSensei's spiritual studies. ŌSensei's early students' documents bear the term aiki-jjutsu. Many of ŌSensei's senior students have different approaches to aikido, depending on when they studied with him. Today aikido is found all over the world in a number of styles, with broad ranges of interpretation and emphasis. However, they all share techniques learned from ŌSensei and most have concern for the well-being of the attacker.