Source: First found on an inscription on a box dated 1385 A.D.
Uchigatana (打刀) literally means "striking sword" when read the classical Chinese way, perhaps a reference to its use for a single-handed strike as if one were using a stick.
It was a further development from the long tachi (太刀) sword that was optimized for use by cavalry. The shorter uchigatana with was optimized for infantry use, wielded in one hand. As opposed to the tachi which was worn slung from a belt, edge down, the uchigatana was worn edge up so it could be quickly pulled and used for an immediate downward strike.1
An uchigatana by Yosōzaemon Sukesada of Bizen Osafune.
Dated to the 3rd year, 8th month of Daiei (大永), corresponding to August 1523 A.D.
Uchigatana seem to appear already in the Heian period (794-1185 A.D.) but are not described with that name.1 The first mention of the word uchigatana comes from the box of a famous sword called hishizukuri-uchigatana (菱作打刀), preserved in the Kasuga-taisha in Nara.2 These early versions were rather short, with 35-45 cm long blades.
The height of popularity of the style was seen in the Muromachi period (1336-1573 A.D.), a period of intense civil war and more of a reliance on foot soldiers than ever before. The uchigatana of this period was longer, from 60-70 cm but retaining its short hilt for single-handed use.
Bizen was the main production center at this time, along with Mino. Both areas made mostly lower grade, purely practical swords but high-end art swords were also produced in particular by Kanemoto of Mino and Sukesada of Bizen Osafune.3
In this period, uchigatana could be worn mounted with a tsuba (guard), or without in a configuration called aikuchi. Many old tachi were shortened in this period to be mounted as uchigatana.4
In the late 16th century the fashion became to wear the long katana (刀) and the shorter wakizashi (脇差), worn together as a daishō“ (大小). It became the symbol of the samurai class, who had the exclusive right to wear both.
1. Markus Sesko; Encyclopedia of Japanese Swords. Self-published. 2014.
2. Markus Sesko; Koshirae, Japanese Sword Mountings. Self-published. 2012.
3. Kōkan Nagayama; The connoisseurs book of Japanese swords. Kodansha America, Inc. 1997.
4. Markus Sesko; Koshirae, Japanese Sword Mountings. Self-published. 2012.