Queen Elizabeth and Prince Philip recently celebrated their 73rd wedding anniversary.

On November 20, Prince William and Kate Middleton shared an adorable photo of the loved-up royal couple reading a card Prince George, Princess Charlotte, and Prince Louis designed for them.

The colorful card is adorned with various hues and shapes. And the queen and Prince Philip were beaming while staring at it.

WHO also revisited the queen and Prince Philip’s love story by stating that they have had the longest marriage in the British royal story.

When the couple wed, Prince Philip gave the queen a ring that, reportedly, has a secret message. As of late, only three people know what’s written in the queen’s ring.

In the book Prince Philip: Revealed, royal author Ingrid Seward said that the queen, Prince Philip, and their jeweler are the only three who know what’s written in the ring.

Since the queen rarely takes off the jewelry, it’s unlikely for other members of the royal family to have spotted Prince Philip’s message.

Prince Philip also, reportedly, kept with British royal tradition that’s why he had the ring made from Welsh gold. Years later, this remained tradition among the royal family because Princess Diana, Kate Middleton, and Meghan Markle’s rings were also made from Welsh gold.

Meanwhile, the queen and Prince Philip first met when the former was just 13 years old and the latter was 18. The monarch’s former governess, Marion Crawford said that the queen was smitten with the Duke of Edinburgh.

After their first meeting, the couple exchanged letters regularly. But things only became serious between the couple when the queen was 17 years old.

Back then, the royal family invited Prince Philip to join them in their Christmas celebration at Windsor Castle. And during that trip, the queen told Crawford that she knows Prince Philip is the one.

Despite the queen’s parents' refusal to give their blessing to her and Prince Philip, the royal couple managed to prove them wrong. The Queen Mother and King George VI eventually allowed the couple to get engaged on the condition that they will keep it a secret for an entire year.

According to WHO, this is because the queen’s parents wanted to give her enough time in case she wants to back out from her engagement.

Following their wedding, the queen and Prince Philip were blessed with four children together. And until today, the Duke of Edinburgh is still the queen’s strength and stay.