Queen Elizabeth II made a rare appearance for dinner with her daughter Princess Anne and first cousin Princess Alexandra in London on Monday. She enjoyed a casual, private dinner at Bellamy’s, a French brasserie and oyster bar located in Mayfair, central London. The 89-year-old British monarch took royal watchers by surprise as she is hardly spotted outside of her official engagements in the city.                   

The 89-year-old, who will celebrate her birthday on April 21, was her impeccable self for the ladies reunion. The queen opted for a sparkling green dress for the outing. It featured long sleeves, high neck, sequins with green border.

She accessorized with a three-string pearl necklace and matching earrings for the royal reunion. Elizabeth carried a small black handbag and wore black low-heeled pumps. She also wore dark lipstick.

She arrived in a separate car from her daughter Anne. The Princess Royal wore a black cape, while her cousin Alexandra was dressed in a full-length violet dress and a black long fur coat. She accessorized with a three-string pearl necklace, drop earrings and wore silver high heels pumps.

Meanwhile, it is not known why the royal trio met, but a spokeswoman for Buckingham Palace declined to comment, saying it was a private dinner.

It's likely that the restaurant will have been closed off to members of the public, so that the Queen and her family could enjoy complete privacy. The Bellamy’s also remained tight-lipped about the dinner. The trio is expected to have dined on the hotel’s signature dishes including steak tartare, venison medallions or grilled swordfish, which all feature on the evening menu.

The hotel serves crème brûlée, tarte tatin and ile flottante for dessert. Bellamy’s holds a special place in Elizabeth’s heart. It’s one of the few restaurants in London that she has dined in. Apart from the hotel, Caviar Kaspia, the French gourmet restaurant that was in the same site, The Ritz and Heston Blumenthal Dinner are some of the other places the queen has dined.

Apart from the royals, Bellamy's is a favorite with many celebrities and A-listers, including Elizabeth Hurley, David Hockney, Kristin Scott Thomas and Princess Alexandra's sister-in-law Princess Michael of Kent.