Yasutsune Itosu, best known as Anko Itosu, is considered more than anyone else to be the father of modern karate. His birth is dated in various sources to 1830, 1831, or 1832, and he died in 1915.

While he certainly did not invent karate himself, his codification of the kata learned from his master Sokon Matsumura and the wide dissemination of his teachings to masters of various traditions that have developed make it a benchmark that any bona fide karate instructor can trace his lineage of teachers back to someone who at least for some period studied with Itosu.

Gichin Funakoshi, founder of Shotokan karate, was a student of Itosu, and both Shito-ryu founder Kenwa Mabuni and Goju Ryu founder Chojun Miyagi were influenced by both Itosu and Kanryo Higaonna , though Mabuni is considered primarily an Itosu student and Miyagi primarily a student of Higaonna. Another influential Itosu student was Shorin-ryu master Choshin Chibana .

Anko Itosu served as a secretary to the last king of the Ryukyu islands until Japan abolished the Okinawa-based native monarchy in 1879. In 1901 he was instrumental in getting karate introduced into Okinawa's schools, and in 1908 wrote the influential Ten Articles of Karate.