It actually goes (and I'd go with this first attribution, because it has been used by a lot of people)...
History is written by the victor.
~ Latin Proverb
Various citings found on the Internet:
"History is written by the winners."
~ Alex Haley, according to at least two print sources, from an interview with David Frost on April 20, 1972.
The so-called lessons of history are for the most part the rationalizations of the victors. History is written by the survivors.
~ Max Lerner
History is written by the victors.
"History is written by the victors."
"History is written by the winners. The books say the Indians were bad guys and the whites just needed a little land. It's like, Excuse me, let me take your car. I'm discovering it. I'm putting my flag on your windshield."
-- Mario Van Peebles