Many of us might have believed that the Russians came up with the idea of nested dolls. But it looks like it went way back to the Egyptians at least. For instance, Tutankhamun's sarcophagus and the shrines were all nested.
The large gold-clad sarcophagus was the outer shell. next to it, you can see the foot of the second sarcophagus that was placed inside of the larger one. And there was a third one, not seen in this photo, which was the actual sarcophagus that held his mummified body.
@randystreat - Depending on the period and the wealth of the individual, it was fashionable to be buried in either one, two, or three different coffins. Multiple coffins would be nested one inside the other.