With one of the largest and most comprehensive collections of historic photography available on the Internet, LIFE's archives offer 33 World War II-related galleries, including dozens of breathtaking images from D-Day. The first photo, and one of the most striking, shows a stern-looking Allied Supreme Commander, Dwight D. Eisenhower, inspecting troops shortly before the Normandy invasion. Another photo reveals a sky reminiscent of a Fourth of July fireworks show, except that it's tracer fire from D-Day's opening phase. Some are more light-hearted, like the image of U.S. serviceman sporting unique, battle-ready haircuts, while others are more gruesome, like Robert Capa's image of fallen Allied soldiers on the beach. But each image is priceless and, somewhat amazingly, available for free.