Daitō-ryū Aiki-jūjutsu (大東流合気柔術, Daitō-ryū Aiki-jūjutsu), originally called Daitō-ryū Jujutsu (大東流柔術, Daitō-ryū Jūjutsu?), is a Japanese martial art that first became widely known in the early 20th century under the headmastership of Takeda Sokaku. Takeda had extensive training in several martial arts (including Kashima Shinden Jikishinkage-ryū and sumo) and referred to the style he taught as "Daitō-ryū" (literally, "Great Eastern School"). Although the school's traditions claim to extend back centuries in Japanese history there are no known extant records regarding the ryū before Takeda. Whether he is regarded as the restorer or founder of the art, the known history of Daitō-ryū begins with Takeda Sokaku. Perhaps the most famous student of Takeda was Morihei Ueshiba, the founder of aikido.