The tanto was a small, rarely used knife. It was mostly carried by the Samurai, and a few other people. Some women carried tantos for self defence againts harmful animals or dangerous people. Before the 16th century, it was common for a Samurai to carry a tachi, which was another type of sword, and a tanto, instead of the the katana and the wakizashi. Ninjas favored the tanto because it was lightweight and was used for assassination.