Born in New York to parents of Italian ancestory, Francis Castiglione is a former U.S. Marine Captain. Before Frank joined the Marines, he was studying to become a Catholic priest but changed his mind because he was unable to forgive those who did evil. Also prior to his enlistment, he married his wife Maria who was already pregnant with their first child. During his time in the United States Marine Corps (USMC), Castle graduated from Basic Training, then went on to Infantry School. Immediately following that, he went through the USMC's Reconnaissance, Force Reconnaissance, and Sniper Schools. Attaining dockets, Castle was permitted to go through U.S. Army Airborne School, and U.S. Navy Underwater Demolition Team training, becoming qualified as a Navy SeAL (Sea, Air and Land). He served in the Vietnam War in a special forces unit as a point man. For heroism in the line of duty, he was decorated with numerous medals, inlcuding the Purple Heart.
Shortly after a tour in Vietnam, Castle, his wife, Maria and their children were in New York's Central Park for an afternoon picnic when they witnessed a Mafia gangland execution; an informant had been hanged from a tree. Seeking to eliminate all witnesses, the Costa crime family murdered them on the spot. However, Castle survived. Even though Frank was able to identify all of the shooters the police were unable to help Castle in his quest for justice; they were tied in too deeply to the powerful Costa family. He decided that the only punishment criminals might receive is that of physical destruction. Shortly thereafter, he emblazoned his body armor with a symbol of a death's head, and exacted his revenge. Since then he has waged a one-man war upon crime, taking the name Punisher.