O' Sensei

Aikido was revealed to the public in 1946. It became one of the fastest-growing martial arts to date. O-Sensei’s Aikido is based not only on Taijutsu (body arts) but also on the use of weapons, namely the Aiki Ken (wooden sword) and Aiki Jo (wooden quarterstaff). 

One of the primary influences on Aikido is Daito-ryu Aiki-jujutsu, a martial art known for its joint manipulation and throws. Ueshiba studied under Takeda Sokaku, a master of Daito-ryu.
Additionally, Ueshiba's proficiency in Kenjutsu, Japanese swordsmanship, and his military experience, particularly with bayonet fighting, shaped the martial techniques, particularly the jo (stick) and ken (sword). 

O-Sensei regarded an understanding of the use of these weapons as fundamental to the proper execution of open-handed techniques but would seldom teach them at the Hombu dojo in Tokyo. He wished for those looking for his Aikido to learn the Aiki weapons at the birthplace of Aikido in Iwama. 

If you want to learn more about the founder of Aikido, the Wikipedia page of Morihei Ueshiba will have a lot of information and references to other sources.