Prince Harry was moved to tears after a wounded U.S. Marine entrusted him with a fallen comrade’s dog tag at Buckingham Palace on Sunday.

The wounded soldier was U.S. Marine Kirstie Ennis, 24. Ennis was among the U.S. Marine soldiers who took part in the Walk WithThe Wounded (WWTW), a thousand-mile journey through the U.K. a charity that helps veteran soldiers.

Prince Harry hugs wounded U.S. Marine at end of 1,000-mile walk https://t.co/YGNZu5HcSL pic.twitter.com/NGypttJYIs

— Huffington Post (@HuffingtonPost) November 3, 2015

Ennis finished the challenge to walk 1,000 miles despite her leg injuries. She was badly injured when her Sikorsky CH-53E Super Stallion Helicopter crashed in Afghanistan in 2012. According to elle.com, she has undergone 38 surgeries and three years of therapy. She was scheduled to be amputated last summer but postponed it so she could join the walk.

Ennis was the only woman to participate in the thousand mile trek that lasted 72 days. Ennis believed the walk was worth the pain and hardships because it was for a good cause.

“I have to remind myself that I have limitations but you have to push those limits to find out what you’re really capable of,” she told the Daily Mirror.

She added that she may not be able to serve in the military, but she still wants to protect her fellow soldiers in the military and to honor the fallen.

Ennis had left 24 dog tags around the country during the trek and planned to leave the last dog tag at Buckingham Palace, but she just gave it to Harry who welcomed them upon completing the challenge.

“No I can’t, I can’t accept this,” Harry said, touched by the gesture. Harry gave her a big hug upon learning how much the dog tag means to her.

The owner of the dog tag was Corporal Baune, who passed away in Helmand province after his unit was hit by a blast from an IED while on patrol.

Ennis walked with other soldiers who had been injured while serving in the military.