After the fall of France, the Wehrmacht found themselves with hundreds of Renault R35 light tanks - a tough if flawed design. Many of these would be used on the Eastern Front to supplement existing stocks of Panzer IIIs and Panzer IVs.
 
The PzKpf 35R/T26 has an interesting history, with some debate about its origins. The prevailing theory is that the vehicle was built by the 7th SS Volunteer Mountain Division Prinz Eugen while they were conducting anti-partisan operations in Yugoslavia.
 
Adding a T-26 turret addresses many of the problems that the original R-35 had. A larger, more spacious turret with a more effective gun makes for a better all-round light tank.