Morihei Ueshiba(1883-1969), known by many as O-Sensei, dedicated himself to the study of Budo. As a young man he trained diligently in several different styles of martial arts and worked to strengthen his physical body. Dissatisfied with mere strength and technical mastery, he also immersed himself in religious and philosophical studies. In a now famous account O-Sensei faced a naval officer, who was a fencing instructor, in a kendo match. Unarmed O-Sensei was able to win the match by evading sword strikes until his opponent fell to the ground in exhaustion. During the match O-Sensei experienced a form of enlightenment regarding Budo. From this and other experiences O-Sensei summarized that true Budo is way of harmony that arises out of the unity of mind-body-spirit.

O-Sensei blended this and other ideas with his martial skill into what became known as Aikido. Today Aikido is practiced around the world by people from all walks of life. The Aikido World Headquarters is located at Hombu Dojo, Japan. The current Doshu is Moriteru Ueshiba, grandson of Morihei Ueshiba.