Prince George and Princess Charlotte are reporting for big sibling duty!

By Erin Hill
April 23, 2018 11:53 AM

Prince George and Princess Charlotte are reporting for big sibling duty!

The brother-sister duo joined their mom, Kate Middleton and dad, Prince William, at the Lindo Wing of St. Mary’s Hospital in London on Monday to meet their new baby brother.

Proud dad William left to pick them up from their family home in Kensington Palace, where they were in the care of nanny Maria Teresa Turrion Borrallo, and brought them back to St. Mary’s to greet the new royal baby.

George, already a big brother two times over, and Charlotte, a new big sister, looked excited as they entered the hospital. George, who was still in his school uniform, and Charlotte, who was adorable in a blue floral dress and a navy cardigan by Amaia, held their dad’s hands as they walked inside. Charlotte smiled and waved enthusiastically to the cameras as she made her way in.

Tim Rooke/REX/Shutterstock

It was a familiar scene, as just three years ago, it was George who arrived with dad William to meet his little sister, Charlotte, for the very first time.

RELATED VIDEO: Happy St. George’s Day! Why Today Has Special Meaning for the Royal Baby’s Birth

The memorable visit echoes Prince William’s own to greet his then-newborn brother Prince Harry in September 1984.

David Fisher/REX/Shutterstock
Gareth Cattermole/Getty

William and Kate welcomed baby No. 3 just hours ago after the royal mom was admitted into St. Mary’s, the same hospital where she gave birth to George and Charlotte.

Tim Rooke/REX/Shutterstock
Dominic Lipinski/PA Wire

The couple’s baby boy is already receiving royal fanfare.

  • Can’t get enough of PEOPLE’s Royals coverage? Sign up for our newsletter to get the latest updates on Kate Middleton, Meghan Markle and more!

The newborn was greeted on social media by everyone from British Prime Minister Theresa May to the London Eye.

Max Mumby/Indigo/Getty Images

“My warmest congratulations to the Duke and Duchess of Cambridge on the birth of their baby boy,” wrote May on Twitter. “I wish them great happiness for the future.”

The London Eye announced that it would light up in red, white and blue to honor the arrival of Prince George and Princess Charlotte‘s younger sibling.