Lady Amelia Spencer, the niece of the late Princess Diana, got engaged to her long-term boyfriend Greg Mallet. The pair dated each other for 11 years before their engagement.

The big announcement was made by groom-to-be Greg Mallet, who is a real estate agent, through his Instagram account. Posting an adorable picture of himself with his fiancée, he revealed that he popped the question to Amelia Spencer, and she said "yes."

"So this was the best day of my life. 22nd of July 2020, I asked the love of my life to spend the rest of her life with me and she said YES. Couldn't be happier and I love you with all my heart," Mallet captioned the photo that gives a glimpse at the newly engaged and Amelia's stunning engagement ring.

Amelia responded to Mallet's message with a comment: "I couldn't love you more. Happiest day of my life!"

Meanwhile, the news was confirmed by Amelia's father Charles Spencer, 9th Earl Spencer, the younger brother of late Princess Diana and maternal uncle of Prince William and Prince Harry. The British nobleman and author of "To Catch A King: Charles II's Great Escape" took to his Twitter to post a message for his daughter.

In his post, he revealed that Mallet asked for his blessing before proposing to Amelia. "So happy for my daughter, Amelia, engaged to her boyfriend of 11 years, Greg - it's wonderful to hear them both so excited about their future. Sending them both love, and every good wish for their life together. I love that Greg asked my blessing before proposing. Very sweet," Charles wrote alongside the photo of the happy couple.

So happy for my daughter, Amelia, engaged to her boyfriend of 11 years, Greg - it’s wonderful to hear them both so excited about their future. Sending them both love, and every good wish for their life together. I love that Greg asked my blessing before proposing. Very sweet. pic.twitter.com/MKx9UpsBJB

— Charles Spencer (@cspencer1508) July 27, 2020

According to E! News, there is no date set yet for their marriage, however, it will have Prince William, Kate Middleton, Prince Harry, and Meghan Markle on its guest list. Princess Diana's sons Prince William and Prince Harry are reportedly "quite close with their cousins" from their mother's side. They were also present at their royal weddings.

princess diana best looks
Some of her best looks were her most relaxed and Diana looked amazing in a pair of simple chinos and white shirt seen here as she attended an engagement at British Red Cross mission in Luanda to highlight the danger of land mines in January, 1997. Getty

Meanwhile, the Spencer family will be enjoying another celebration when Amelia's older sister Lady Kitty Spencer gets married to her fiancé Michael Lewis, next summer.