Daitō-ryū Aiki-jūjutsu
Aikido is a modern martial art developed primarily during the late 1920s through the 1930s by Morihei Ueshiba from the system of Daitō-ryū Aiki-jūjutsu. Ueshiba was an accomplished student of Takeda Sokaku with aikido being a systemic refinement of defensive techniques from Aiki-Jujutsu in ways that are intended to prevent harm to either the attacker or the defender. Aikido changed much during Ueshiba's lifetime, so earlier styles (such as Yoshinkan) are more like the original Aiki-Jujutsu than ones (such as Ki-Aikido) that more resemble the techniques and philosophy that Ueshiba stressed towards the end of his life.