October 10, 1859 – April 25, 1943
Takeda Sokaku was a reknowned martial arts master of Daitō-ryū Aiki-jūjutsu and Ono-ha Itto-ryu swordsmanship. During his lifetime he is credited with teaching many famous martial artists among them the swordsman Shimoe Hidetaro, Aikido founder Ueshiba Morihei, as well as many politicians, military officers, judges, policemen, and other persons of high social standing from all over Japan.
December 14, 1883 – April 26, 1969
Morihei Ueshiba (O Sensei), was a skilled exponent and teacher of Daitō-ryū Aiki-jūjutsu. Many of his recognised first generation Aikido students were awarded menjo certificates bearing the Daitō-ryū designation. As Ueshiba grew older, more skilled, less physically able and more spiritual in his outlook, his focus and teaching changed, became softer and more circular, striking techniques becoming less important and his curriculum simpler leading eventually to the formulation of his own distinct school, which he promoted later under the banner Aiki-Budo and Aikido. After his death, and a period of reorganisation, his son Kisshomaru Ueshiba took on the mantle of Doshu (hereditary head) andoversaw the formation of the Aikikai Honbu organisation.
March 15, 1900 – December 25, 1979
Kenji Tomiki was the first student to be awarded a teaching menjo (Menkyo Kaiden or license of transmission, equated later to an 8th Dan) by the founder of Aikido, Morihei Ueshiba. A renkowned and active teacher of both Judo and Aikido throughout his life, Professor Tomiki formulated a new method of teaching Aikido suitable for adoption by universities as well as introducing competitive Aikido (Aikido kyogi) into regular practice. A serious rift occurred with the direct decendents of Morhei Ueshiba in respect to his approach to competitive practice leading to his resignation as technical director of the Aikikai. This led to his formation of the Japan Aikido Association and the creation of the Shodokan Dojo where he continued his research. Aikido taught using the teaching and practice methods of Kenji Tomiki is often referred to as Shodokan Aikido, Tomiki Aikido and/or Sport Aikido.
Read more about Kenji Tomiki and Shodokan Aikido here