On Thursday, Kate Middleton and Prince William attended The Royal Variety Performance at the London Palladium. The Clarence House released a photo via social media site, Twitter, of the royal duchess being greeted by One Direction's Harry Styles, who was set to perform at the stellar event.

During the royal meeting with One Direction, Kate Middleton looked stunning in a Diane von Furstenberg black lace gown with long sheer sleeves, the Duchess of Cambridge completed her look with a pair of diamond drop earrings and a stylish chignon. While Prince William appeared elegant in a traditional black tuxedo.

The royal couple, Kate Middleton and Prince William completed another royal responsibility when they attended The Royal Variety Performance event on Thursday. The pregnant duchess concealed her tiny baby bump in a gorgeous black dress. Vanity Fair said their royal appearance have been an enjoyable one after the event was graced by famous celebrities such as One Direction, Bette Midler, Ed Sheeran, Ellie Goulding and Simply Red, among others.

The One Direction boys later shared their experiences on the royal meeting with Kate and William.

"I said congratulations on the bump," One Direction's Harry Styles said. "She didn't look bumpy." Meanwhile, Liam Payne said after the royal meeting, "The most nervous I think I've ever been in my life." And Louis Tomlinson regretted not calling Kate Middleton "Ma'am," retelling, "I said 'Hi. How are you? I'm Louis.'"

At the royal meeting, Prince William reportedly talked with One Direction about their touring plans, which the prince has been "keeping a close eye on," as said by News.com.au. The star-studded event was hosted by Michael McIntyre along with singers Ed Sheeran and Demi Lovato.

The Royal Variety Performance takes place annually and proceeds are donated to The Entertainment Artiste's Benevolent Fund, which Queen Elizabeth II is a patron. As said by Mirror UK, the fund cares for hundreds of entertainers all throughout United Kingdom who need help and assistance as a result of old age, ill-health or difficult struggles.

Traditionally, the event was attended by the Queen Matriarch while taking turns with the Prince of Wales. This year, it has been expected that the monarch will be seated in the royal box but the attendance of Prince William along with wife Kate Middleton shows how the younger members of the royal family are stepping in to help the Queen.

When asked if the Duke and Duchess of Cambridge will take in turns with the Prince of Wales, a Buckingham Palace spokesperson said through a statement.

"As with any other invitation, attendance by the Queen and the Duke of Edinburgh will be assessed on a case-by-case basis," a palace spokesman said.

Meanwhile, at the royal meeting with Kate Middleton and Prince William, Ok Magazine revealed the One Direction boys particularly Zayn Malik and Harry Styles pulled up an extra effort with their appearances by sporting long, disheveled haircuts.

For the first time to watch The Royal Variety Performance, the pregnant Duchess of Cambridge, Kate Middleton looked stunningly radiant despite early struggles with severe morning sickness, as she and husband Prince William shook the hands of casually dressed One Direction.