“As the birth day approached, Kate threw herself into preparing her royal nest. She spent time getting the temporary nursery at Nottingham Cottage, in the grounds of Kensington Palace, ready.”

Mr Jobson described Kate and William as “royal trendsetters” throughout the pregnancy as they introduced “far greater informality” to the process.

However, building work at Nottingham Cottage was delayed when asbestos was discovered in apartment 1A, a four-storey house that forms half the Clock Tower Wing.

“For Kate, one of the main attractions of the house, designed by Christopher Wren in the 17th century, is the beautiful walled garden, perfect for pushing the baby around and indulging in some gardening,” the journalist and broadcaster wrote in his book.

“With the help of her mother, Kate had been choosing furnishings and fabric for the house in very much the same way that Diana did 30 years before.”

Prince William also has his own nicknames, including one given to him by his late mother Diana – ‘Wombat’. In a 2007 interview with NBC’s Matt Lauer, he explained: “It began when I was two. I’ve been rightfully told because I can’t remember back that far. But when we went to Australia with our parents, and the wombat, you know, that’s the local animal. So I just basically got called that. Not because I look like a wombat, or maybe I do?!”

Mr Jobson wrote in the book that Kate meanwhile, was nicknamed “Squeak” as a young girl at St Andrew’s School in Berkshire. She explained how the name came about while on a visit to the school years later.

“I was nicknamed Squeak just like my guinea pig,” she said. “There was one called Pip and one called Squeak because my sister was called Pippa and I was Squeak.”