Hanneman was born January 31, 1964 in Oakland, California, and grew up in Long Beach, California in a family containing several war veterans: his father fought in Normandy during World War II and his brothers in Vietnam, making warfare a common conversation topic at the dinner table. War films were popular on TV at the time, and Hanneman often joined his brothers in constructing and coloring tank and plane models. His interest in warfare and military history has been attributed to his upbringing.