A study reported in Phys.Org says that the peak population of Neanderthals in Europe occurred between 43,000 and 60,000 years ago. Sudden extinction of Neanderthals followed population peak They then died out rather quickly after the 43,000 year limit.

The peak population was not very big. One popular estimate suggests that the population of Neanderthals in all of Europe may have been around 70,000 people. More recent estimates indicate that the population may have been much smaller than that.

Bill Gill

C is not the speed of light in a vacuum.
C is the universal speed limit.