Chairman Prescott

From Gears of War - Wiki on Neoseeker

The leader of COG, he played a very important part in keeping humanity alive during and after Emergence Day. In Gears of War 2, he will be the one to give a motivational speech before sending troops to fight the Locust Horde in a final stand for the survival of mankind. Not much is known about him due to the lack of knowledge provided about him during the game. But some believe that he is a former COG, but this is just a rumor. he does not play a big part in any of the games apart from his speech in the new game.