Narex Bystrice, were originally called Vaclav Richter and have been going since 1919 in the same building.
Unlike western manufacturers they didn't go down the impulse hardening route (a fast, cheap but not particularly accurate hardening method which I believe contributed significantly to the fall in quality among most, but not all, western brands in the 1960s).
Instead Narex were effectively a department of a huge state owned company with all the associated research and development funding to find another way to make very good blades in vast quantities.
The result was the isothermally hardened CrMn that they still use today.