I was deeply saddened, though not particularly surprised, to hear of the passing of Samuel V. Wilson. “General Sam,” as he was widely known in his corner of rural Virginia, had been living under a death sentence, having been diagnosed at the age of 93 with lung cancer. It was only a matter of time. But somehow that does not lessen the shock of realizing that this giant of a man, who had racked up so many momentous accomplishments in his country’s service, is no longer with us.

Who was Sam Wilson, you may be asking? He was no household name. He was merely another member of the Greatest Generation who did his duty—and then some. As his friend, the war correspondent Joe Galloway, recounted, Sam lied about his age in 1940—he was only 16—to enlist in the National Guard straight out of high school. Before long he wound up as a first lieutenant operating behind Japanese lines in Burma with the famed Merrill’s Marauders, an early special operations unit that suffered devastating casualties.

“The Army tried to send him to West Point in 1945 but Wilson couldn’t pass the physical because of lingering health problems from his service in the tropics–typhoid fever, malaria, amoebic dysentery,” Galloway wrote. “Instead, he went to Columbia University and began five years of intensive study of Russian there and in occupied Germany. That was the first of eight languages he would master, among them French, German, Spanish, the Kachin dialect of Burma, and Mandarin Chinese.”

Thus did Wilson launch a career that would be spent in the top-secret worlds of special operations and intelligence work. He was detailed to the CIA while remaining on active duty and, according to Galloway, even served as both a defense attaché and CIA station chief in Moscow at the same time. Rising to the rank of lieutenant general, he became a deputy CIA director and then director of the Defense Intelligence Agency in the 1970s.

Along the way he played a pioneering role in the special operations field, having helped to create Delta Force in the late 1970s and making a plausible claim to having coined the word “counterinsurgency” in the early 1960s at a time when he was one of the first instructors in the subject at Ft. Bragg. Later, he got to apply the lessons he was teaching while serving in Vietnam.

I met “General Sam” three and a half years ago when I traveled to his home in the rural community of Rice, Virginia, where he had grown up, to interview him about his work with the legendary Edward Lansdale—a swashbuckling covert-action specialist who is the subject of a biography I have just finished. (The Road Not Taken: Edward Lansdale and the American Tragedy in Vietnam will be out in January.) Wilson had served as Lansdale’s assistant at the Pentagon in the late 1950s and early 1960s when Lansdale was in between tours in South Vietnam, a state Lansdale had done much to create.

Wilson was already infirm, but he was still big, rugged, and handsome. His mind remained as sharp as a bayonet, as he sat on his back porch and recounted to me the influence that Lansdale had had on his life and career. He was remarkably clear-eyed about Lansdale’s achievements as well as some of his shortcomings. At one point, hearing a bird’s call, he stopped talking and winced. I wondered why. In his soft Virginia accent, he explained:

“That’s a pileated woodpecker. He’s about the size of a crow…. That cry is an almost exact replication of the calls of the gibbon monkeys in Southeast Asia. Matter of fact, the day after I retired from the military I was sitting here on this porch. I heard one and my blood ran cold. I thought my God. We, behind the Japanese lines, would listen when the gibbon monkeys where over the ridge chattering away as the tribes fed. Then when they’d suddenly go quiet we would know that either a wild elephant or a tiger was moving through their feeding area or a Japanese patrol. Learned quickly to know that if the interval of silence was brief that it was one of the wild animals going by one of the enemies. If it lasted for a while, in all probability, it was the Japanese patrol. We were always relieved when it took up again.

“I listened to that call several times and then I went back to my piano and I picked it out. I finally came to realize it was the same call. The same spacing…. Only an octave higher than the gibbon monkeys. When I hear it I still get a little prickle at the back of my neck. If you see me wince and look around, it’s not a tick.”

Here we were in Virginia in 2013, but some portion of his mind was still back in Burma in 1944 where he had first risked his neck and made his mark as an American soldier and intelligence officer.

Few others could rival Wilson’s achievements across so many fields—to include his work as president of Hampden-Sydney College in Virginia after his retirement. If there were any justice, General Sam would deserve to be far better known. But having operated most of his life in the shadows, he appeared content with his relative anonymity. He epitomized the Special Forces ideal of the “quiet professional.”