So late Christmas night, Washington and his troops hopped in boats and waded across the icy Delaware River to test his theory – and he was right. At dawn on Dec. 26, about 2,400 frozen Continentals pushed into Trenton, and they did indeed surprise the enemy, who surrendered within an hour and a half.
https://www.defense.gov/explore/story/Article/1713087/4-major-military-events-that-happened-on-christmas/#.XB5oayjM_GM.twitter
Christmas Day