Prince Harry and Meghan Markle
Prince Harry was inspired by James Hewitt to join the army. Pictured: Prince Harry and Markle attend The Prince of Wales' 70th Birthday Patronage Celebration held at Buckingham Palace on May 22, 2018 in London. Getty Images/Dominic Lipinski

James Hewitt influenced Prince Harry to join the army, according to a biographer.

Prince Harry's life changed when he joined the army. In fact, the Queen's former private secretary described the new duke as a "playboy." Before he began his time in the Services, he earned something of a "playboy reputation," Sir William Heseltine said about Meghan Markle's husband.

According to journalist Angela Levin in her new biography "Harry Conversations with the Prince," Prince Harry was inspired by Hewitt to join the army. The British former cavalry officer reportedly took the prince to visit Combermere Barracks in Windsor. It was at that time when Prince Harry exclaimed that he was "going to be a soldier when I grow up."

"The soldier-mad toddler was fascinated by everything to do with the army, so it's no surprise he took to Hewitt straight away," Levin explained. "He wore a military uniform, rode horses and made his mummy happy. Harry was always incredibly close to his mother and when Diana showed strong feelings for Hewitt he followed her example."

"Harry was engrossed by Hewitt's military stories and thrilled when he arrived at Kensington Palace, and he and William were allowed to come downstairs after their bath and spend time with him," the royal biographer continued.

Hewitt had a five-year affair with the late Princess of Wales. In fact, there were speculations that he was Prince Harry's biological father because the Duke of Sussex's appearance is closer to him than to Prince Charles. But Paul Burrell, Princess Diana's butler debunked the rumors.

"It's something that's been made up. It was just because Harry had red hair, but all the Spencers have red hair," Burrell said.

The People's Princess' bodyguard Ken Wharfe also denied the rumors. In his book "Diana: Closely Guarded Secret," he wrote that "the malicious rumors that still persist about the paternity of Prince Harry used to anger Diana greatly."

"Harry was born on 15 September 1984. Diana did not meet James until the summer of 1986, and the red hair, gossips so love to cite as proof is, of course, a Spencer trait," Wharfe explained.

Hewitt, himself, also denied the rumors. According to him, Prince Harry was already a toddler when he met Princess Diana.

"There really is no possibility whatsoever that I am Harry's father," Hewitt told Sunday Mirror in 2012. "I can absolutely assure you that I am not. Admittedly the red hair is similar to mine, and people say we look alike. I have never encouraged these comparisons and although I was with Diana for a long time, I must state once and for all that I'm not Harry's father. When I met Diana, he was already a toddler."