Children of US Veteran Pictured in Prince Harry's Christmas Card

Anthony Radetic's kids met Prince Harry at the Invictus Games.

— -- The Radetic family of Abbeville, Alabama, had a royal surprise when they opened their mail earlier this week.

“My daughter was really excited. She couldn’t believe it,” Anthony Radetic told ABC News. “My son is a little young to grasp it but he was still really happy.”

Radetic, a retired U.S. Army helicopter pilot, is the reason his children met Harry last summer at the Invictus Games in Orlando.

Radetic was paralyzed from the waist down more than six years ago in a motor vehicle accident at Fort Rucker, an Army post in Alabama. He is now a full-time competitive athlete and was a member of the U.S. team at both the 2014 and 2016 Invictus Games.

Harry, himself a veteran, created the Paralympic-style Invictus Games as a way to draw attention to and inspire wounded servicemen and women.

“He’s out there constantly with all the veterans and soldiers throughout the event,” Radetic, who competed in swimming and basketball, said of Harry. “And while we were competing, the families would get to meet him.”

Radetic said his daughter, Ana-Maria, did not meet Harry during the London games so she was “determined” to meet him in Orlando. When she and Vinko met him in Orlando, they took the photo that became Harry’s Christmas card.

“They got to meet a lot of celebrities and they said Harry was by far the nicest, kindest and most genuine person they met,” Radetic said.

Radetic said a member of Harry’s team reached out to him earlier to let him know it was a possibility the photo would be used. He did not know for sure until his children opened the card and saw the photo and a note from Harry that read, "Thank you for making my Christmas card."

“It was really a surprise,” he said. “It’s really amazing, actually.”

Radetic described it as an “absolute honor” to know Harry and have him as a “big advocate” for military veterans.

“He’s the perfect spokesperson and him coming up with the Invictus Games was only fitting,” said Radetic, who hopes to compete in the 2017 Invictus Games in Toronto.