Prince Philip was “crucial” in helping to “coach” his grandson Prince William for his future role as King.

The Duke of Edinburgh – who sadly passed away on April 9 at the age of 99 – was the longest-serving consort to any British monarch, having married Queen Elizabeth II when she was still a Princess 73 years ago and spending 69 years as her consort.

And with plenty of experience of being married to a monarch, Philip reportedly played a key role in teaching his grandson William everything he needed to know about one day becoming King.

Historian Robert Lacey told People magazine: “Philip was crucial in helping coach William as a future King. It was Philip’s idea to set up the lunches between William and his grandmother. When the time came for the Queen to talk business with William, Philip would quietly excuse himself because he didn’t feel that the constitutional side of the Queen’s job was something he wanted to interfere in.”

Prince Philip passed on “elements of the serious and the fun” to his grandson – who is second in line to the throne behind his own father, Prince Charles – as well as William’s younger brother, Prince Harry.

Royal biographer Penny Junor told the publication: “[Harry] very much got his sense of duty and active service from his grandfather.”

Meanwhile, Philip was laid to rest over the weekend, and his grandson-in-law Mike Tindall – who is married to Zara Tindall – recently said the ceremony was exactly “how he would have liked it”.

He said: “It’s been a difficult 10 days. If I look back on the day, as eerie as it was with no crowds and social distancing [because of COVID-19], and the way everything was, I think it was the perfect day, how he would have liked it, if that makes sense whatsoever. No fuss, get on with it.”