Daitô-ryû Aiki-bujutsu is a form of self-DEFENSE that was developed 900 years ago and transmitted only within the Takeda family of the Aizu clan; it is the forerunner of the modern Aikidô. As it is a system that is characterized by the word aiki (literally, 'joining of energy'), those who excel at this art can completely control all opponents, regardless of their strength or body size, making this an excellent self-DEFENSE art. Daitô-ryû Aiki-bujutsu is a school of martial arts that was founded in the late Heian period (around the beginning of the twelfth century) by a great warrior known as Shinra Saburô Minamoto no Yoshimitsu (1056-1127) of the Minamoto-ryû, which it_self is mentioned in the eighth-century Records of Ancient Matters (Kojiki). The techniques of the Daitô-ryû were well known to medieval warlord Takeda Shingen (1521-73), as they had long been passed down only within the Takeda family, descended from Yoshimitsu's second son, Yoshikiyo, who formed the Aizu clan of northeastern Japan. The modern proponent of Daitô-ryû Aiki-bujutsu was Sôkaku Takeda (b. 1860), the direct descendant of Yoshimitsu, who studied not only the techniques of his own school, but also those of such various arts as Hozoin-ryû sôjutsu (spear techniques), kenjutsu (swordsmanship), and sumô (grappling); Ono-style Ittô-ryû kendô (swordsmanship); Jiki Shingan-ryû kenjutsu; Mukai-ryû suichû-jutsu (swimming in armor); and Okinawa-te (the precursor of karate). Master Hidemine Jibiki studied the art of Daitô-ryû Aiki-bujutsu under two of Takeda's senior students, Tsunejirô Hosono and Kôtarô Yoshida. As a "soft-style" martial art, the essential principle of the form is to conquer the opponent with any and all means with the least possible exertion of force; rather, one must produce inner energy (Ch: ch'i; Jpn: ki) with which to meet (ai) the force of the opponent; thus, it uses the opponent's own force against him. The essence of Aiki-bujutsu is said to have been retained only within the Daitô-ryû tradition. It is interesting to note here that Aiki-bujutsu, which is deadly when used in combat, is also the ancestor of the martial arts-cum-sports later developed by Jingorô Kanô (Judô) and Morihei Ueshiba (Aikidô).