Queen Elizabeth and Prince Philip enjoy a long and enduring marriage together for 72 years and counting. But, the Queen was once a budding 21-year-old when she married Prince Philip, who was then 26. As any newly-wed, the royal pair had their moments together and at one point, a royal staff walked in on them during their intimate moment. 

According to royal biographer Philip Eade, who wrote the book "Young Prince Philip: His Turbulent Early Life," the royals lived in Clarence House as newly-weds for two years. Prince Philip and the then-Princess Elizabeth had separate bedrooms, which was a common arrangement between the upper class and aristocrats during their time.  

Their bedrooms, however, were next door to each other and had a connecting door between the walls. The royal pair took advantage of this door to enjoy their "visitation rituals." 

One morning, Prince Philip's valet saw that the princess was on the bed of her husband. While she was still dressed in her silk nightgown, her husband was visibly naked and didn't care at all that the valet saw them. 

In fact, it was the valet who was embarrassed for walking in on the royal couple during their intimate time together. The valet, John Dean, believes that the first few years of the royals' marriage was Prince Philip's happiest times. 

Their honeymoon as a newly-wed was cut short when Princess Elizabeth ascended the throne following the death of her father, King George VI, in 1952. It was an unexpected passing as everyone thought that the king, who was only 51 years old at that time, would continue his reign for 20 years more. 

No one was more devastated about their new royal responsibilities than Prince Philip. He knew that their freedom as newly-weds and new parents would soon come to pass as they will be called upon to serve the Crown full time. 

Nevertheless, Queen Elizabeth and Prince Philip did dedicate their life to the Crown until the Duke of Edinburgh retired in 2017. Her Majesty, however, remains the monarch and will continue to be the ruler until her dying day.

Incidentally, it's been 68 years this February since Queen Elizabeth ascended to the throne. In celebration of this milestone, the King's Troop Royal Horse Artillery had a gun salute at the Tower of London. The bells of Westminster Abbey also rang out to celebrate Ascension Day.

Queen Elizabeth holds the record for the longest-reigning living monarch.