Kenjutsu (剣術), which predates modern kendo, is the art of using the Japanese sword. The term usually refers to the methods or techniques of swordsmanship of traditional schools, called Koryū (古流), i.e. Japanese martial art schools that were founded before 1868 (Meiji restoration).
Although Kendō (剣道,lit. “The way of the sword”) can be used to indicate Japanese swordsmanship in general, these days it is most often used for what can be called “Shinai-kendo” (modern kendo using bamboo swords, called “shinai”).
Kenjutsu would flourish in the late Edo period, before to go into a temporary decline following the Meiji Restoration, when Japan started with the development of modern, European-style armed forces. Kenjutsu became unpopular until, in 1879, the Tokyo Police Force and later the army initiated Kenjutsu practices again. However, after the Meiji restoration, modern disciplines were preferred over old traditions. Parallel to the development of kendo, several Iaido organizations emerged, following the general trend to replace the suffix “-jutsu” with “-dō” in order to emphasize the spiritual/philosophical aspect. The quick-drawing sword techniques (known as “Batttōjutsu”) were turned into the martial art called “Iaidō” ("the Way of Harmonious being”).
After Japan's defeat and occupation in 1945 by the Allied Powers public instruction in Kendo was banned because of its involvement in wartime indoctrination. It was not fully rehabilitated until 1953 after the Korean War had ended. At that time, few people were as influential as Sasamori Junzō (1886—1976), who founded and served as the president of the Zen Nihon Shinai Kyogi Renmei (All Japan Federation for Bamboo Stick Competition). Sasamori Junzō besides being Sōke Ono Ha Ittō Ryū also achieved 10th dan and was author of the book “This is kendo”. With the focus on competition, using shinai (made of bamboo) and typical protective gear, interest in the traditional sword fighting techniques declined again. Moreover, Iaido evolved into one of the most popular sword arts of Japan.
Despite all this, several old schools survived and continue to preserve their important Japanese heritage. Amongst them, Ono Ha Ittō Ryū (小野派一刀流) still is one of the most influential traditional Kenjutsu schools in Japan.
More information on traditional Japanese schools can be found in the next article: Traditional Japanese Martial Systems