The Duke of Sussex has revealed that he killed 25 people while serving as an Apache helicopter pilot in Afghanistan.

In his autobiography Spare, Harry said he did not think of them as “people” but instead as “chess pieces” that had been taken off the board.

The Telegraph, which obtained a Spanish language copy of the memoir from a bookshop in Spain, revealed that Harry wrote that flying six missions during his second tour of duty on the front line resulted in “the taking of human lives” of which he was neither proud nor ashamed.

Describing watching a video of each “kill” when he returned to base, he wrote of Taliban fighters as “baddies” who were being eliminated before they could kill “goodies”.

“So, my number is 25. It’s not a number that fills me with satisfaction, but nor does it embarrass me,” he wrote.

Harry first went to war in 2007 on a 10-week tour of duty fighting the Taliban in dangerous Helmand Province, operating as a battlefield air controller behind enemy lines.

The secret mission – which ended early after it was leaked on the internet – gave him the opportunity to be treated as a real soldier, rather than a prince.

He returned dubbed the “Warrior Prince”, “Harry the Brave” and “One of Our Boys” by the press for fighting for his country.

With a burning desire to return to Afghanistan, Harry retrained and qualified as an Apache helicopter pilot after rigorous training in Britain and America.

In September 2012, he made it back to Afghanistan for a second time.

The 20-week stint gave him the chance to use his Apache flying skills and head out on operations in his role as co-pilot gunner.

But he was criticised on his return to the UK for frank comments that he took the enemy “out of the game”, and soldiers “take a life to save a life”.

As a gunner in Apache attack helicopters, the royal, who was then 28, flew on scores of missions with his fingers on the triggers of deadly rockets, missiles and a 30mm cannon.

“Take a life to save a life,” he shrugged and said during an interview in 2013. “That’s what we revolve around, I suppose.

“If there’s people trying to do bad stuff to our guys, then we’ll take them out of the game, I suppose.”