Queen Elizabeth II was the longest-reigning monarch in British history, the only monarch most Britons have ever known. She ruled during a transformative period of human history and became queen of an empire at 25. She met 13 presidents in her lifetime and received bows or fist bumps from each of them for a reason: A record like hers commands respect, even from the Leader of the Free World. Probably one of the few things former presidents would agree on these days is their respect for Queen Elizabeth II. Here are a few military stories from her life.