Theorems' names that don't credit the right people The point of this question is to compile a list of theorems that don't give credit to right people in the sense that the name(s) of the mathematician(s) who first proved the theorem doesn't (do not) appear in the theorem name. 
For instance the Cantor Schröder Bernstein theorem was first proved by Dedekind.
I'd also like to include situations in which someone conjectured something, didn't prove it, then someone else conjectured the same thing later, also without proving it, and was credited with having first conjectured it.
Similar unfair things which I didn't remember to include might also be considered.
Some kind of reference is appreciated.

Nobody's mentioned the Pythagorean theorem yet?
