Ado's Theorem is a very reelvant result in Lie theory (every finite-dimensional Lie algebra is isomorphic to a matrix Lie algebra).
I've been, however, unable to find anything more than very basics information on who is the mathematician that proved it. Igor Ado (1910-1983), student of Chebotaryov, graduated in Kazan University in 1935. And basically that's all.
Does anyone know of some more related informations?