The Hunslet Engine Company was founded in 1864 at Jack Lane, Hunslet by John Towlerton Leather. The works was established on a plot of the former E.B.Wilson Railway Foundry. By this time Manning Wardle were already well established next door to the former Wilson works and had effectively taken over from the old firm. Hudswell, Clarke & Company had also established a new works in a plot of the former Wilson land and these firms joined the already well established Kitson works nearby on Pearson street.
The first engine built in 1865 was a standard gauge 0-6-0 saddle tank delivered to Thomas Brassey at Ampthill in Bedfordshire and was used on the construction of the Midland Railway.
During the 1920's recession some of the other independent British manufacturers failed to survive the 1920s and 30s and Hunslet acquired the patterns, rights and designs of other builders including Kerr Stuart and the Avonside Engine Co. And in the 1970's & 80's they bought out Scottish firm Andrew Barcley and local firms Hudswell Clarke and Greenwood and Batley.
Hunslet had been interested in internal combustion very early on, in fact back in Edwardian times they produced some early motor cars under the 'Attila' brandname.