Amal Clooney dons unexpected accessory with husband George Clooney at Buckingham Palace Editors

It was a royal night out for George and Amal Clooney.

The A-list couple stepped out for a private dinner in honor of The Prince's Trust at Buckingham Palace on Tuesday night in London, which was hosted by none other than Prince Charles.

The star-studded event, which also boasted Benedict Cumberbatch, Luke Evans, Chiwetel Ejiofor and Josh Hartnett as guests, was held for donors of the aforementioned trust, which is dedicated to provide aide to underprivileged youth who are either unemployed and looking for an education.

SEE ALSO: Amal Clooney makes rare outing with her twins: Photos

For the event, Amal opted for a strapless white Jean-Louis Scherrer gown by Stephane Rolland from William Vintage, which she paired with a chic asymmetrical cape and an unexpected beaded sleeve on her left arm. The human rights lawyer's actor husband looked dapper as ever in a classic tux and burgeoning beard.

See photos of the couple at Buckingham Palace:

Inside of Buckingham Palace, the couple was photographed sharing a friendly greeting with Prince Charles and posing alongside the other celeb guests for a group photo.

This isn't their first run-in with the royal family: George and Amal attended Prince Harry and Meghan Markle's royal wedding last May, and Amal attended Meghan's lavish New York City baby shower back in February at The Mark Hotel on the Upper East Side.

See photos of from Meghan's baby shower below: