The former special counsel in the hot seat Tuesday at a pair of contentious House hearings over his probe into Russian election meddling has a history of keeping cool under fire.

Robert Mueller, who delivered mostly terse answers and showed little emotion during the first two hours of the House Judiciary Committee hearing, was a decorated war hero in Vietnam, winning both a Purple Heart and a Bronze Star for bravery as a Marine platoon leader.

Born in New York, the 74-year-old Mueller attended the elite St. Paul’s school in New Hampshire, where he captained the soccer, lacrosse and hockey teams.

He then attended Princeton University, and enlisted in the Marines upon graduation in honor of a friend who had been killed in combat.

After he was discharged, he earned a master’s degree from NYU and his law degree from the University of Virginia and went to work for the Justice Department, serving as a federal prosecutor in California, Massachusetts and DC.

The 6-foot-tall Mueller was appointed FBI director by President George W. Bush on Sept. 4, 2001, and was barely on the job when the 9/11 attacks occurred. He spent the next years revamping the bureau to deal with terrorism and other 21st-century threats.

He was kept on by President Barack Obama before stepping down in 2013 to work in private practice.

On May 17, 2017, he was appointed special counsel to probe Russian election meddling and possible collusion with the Trump campaign, a job he kept until May of this year.

Mueller has been married for more than 50 years to Ann Cabell Standish and they have two adult children.