If you've ever felt nervous about meeting your other half's parents, spare a thought for Meghan Markle.

It's hard to believe it but it's less than a year since she and Prince Harry announced their engagement. Not long before that, she went to Buckingham Palace to meet his grandmother, Queen Elizabeth, for the first time and it sounds like it was a fairly big deal. The queen had certain reservations about Harry, according to a new biography, and her blessing was far from guaranteed. In an excerpt from his new book 'Meghan: A Hollywood Princess', royal expert Andrew Morton writes that Meghan's first encounter with the monarch "was the most important audition of Meghan’s life."

“When she was driven through the gates of Buckingham Palace on an overcast, drizzly Thursday in October in a black Ford Galaxy with darkened windows, the actress was about to give the performance of her career. “No rehearsal, no script, no second takes. This was live and improvised."

There was "an air of tension", Morton continues.

"This was perhaps inevitable. As fifth in line to the throne the prince had to obtain his grandmother’s formal permission to marry. "It was by no means a foregone conclusion. She could say no. She’d done it before. Then what? "Any possible uncertainly about the outcome of this meeting lay not with Meghan, but with the man she wanted to marry. “He was the one who had been, if not on trial, then under close scrutiny. "If he had come to see Grannie a few years earlier when he had an unenviable reputation as an angry drunk with poor judgement, it would have been doubtful that the Queen would have agreed to him marrying a divorced American actress. “Harry’s transformation over the last few years has, together with the popular union between Prince William and Kate Middleton, secured the future of the monarchy.”

We can only imagine that the meeting went well, given that Harry and Meghan were engaged less than a month later. Author Andrew Morton has something of an inside track on the royals. His explosive 1992 book 'Diana: Her True Story' lifted the lid on the unhappiness that Harry's mother felt in her marriage to Prince Charles and was written using the princess's own first-hand accounts.