Kate Middleton and Prince William debut their royal baby princess!

Say hello to your new princess! Prince William and a glowing Kate Middleton proudly introduced their new baby to the world outside St. Mary's hospital in London on Saturday. The beloved royal couple smiled and waved as hundreds gathered outside the hospital to catch a glimpse of the new addition to the British royal family.

Kate and William presented their new bundle of joy Photo: Getty Images

A glowing Kate, dressed in a yellow floral print dress by Jenny Packham and nude pumps, held her newborn outside the Lindo Wing where she previously displayed her firstborn Prince George in July 2013. Kate previously wore the British designer when she debuted George.

Kate looks very much in love with her new baby Photo: Getty Images

Swaddled in a white G. Hurt & Son blanket and wearing a little bonnet, the newest member of the royal family slept peacefully, oblivious to the global excitement surrounding her anticipated arrival.

Earlier in the day, 21-month-old George was right by his mom and dad's side as he met his new sister.

Too cute: Father and son wore matching clothes Photo: Getty Images

Upon arrival to the hospital, George matched his father in a blue sweater, but wore his with shorts and high socks. As William and George made their way from his car to the steps of the Lindo Wing, George wanted to be carried. As they posed for photographs, the toddler did manage to wave to those lined up.

Both Diana and Kate wore sweet polka-dots when unveiling their firstborn sons Photo: Getty Images

Right after George's birth, William was in a joyous mood and went out of his way to thank the crowd and press for their support. He even acknowledged those who were camped out for days in tight quarters. "I'll remind him of his tardiness when he's a bit older," Will told gathered fans, "because I know how long you've all been standing here so hopefully the hospital and you guys can all go back to normal now and we can go and look after him."

Same goes for the Princess of Cambridge! She joined the world several days after her original due date in the middle of April. George was not by his sister's side as William, Kate and their baby girl left the hospital. Kensington Palace tweeted that George returned home around 5:30 PM UK time.

A beaming Kate looked on adoringly at William in July 2013 Photo: Getty Images

St. Mary's has long been a tradition within the royal family. Aside from Kate's first birth, Princess Diana also gave birth to William and Harry in the Lindo wing of the famous London hospital. Although it's the same hospital, the newly refurbished Lindo Wing is far more luxurious than when Diana gave birth in 1982. It features high-end amenities reminiscent of a hotel and over 40 pieces of art by London artist Julian Opie.

Charles and Diana introduced Prince Harry to the world outside St Mary's as well Photo: Getty Images

While it's the second child for the young royal couple, the excitement surrounding the birth is just like with George. Fans and members of the press were all too happy to greet the newest heir to the British throne.

The new royal was revealed to the world on Saturday Photo: Getty Images

We can't wait to get to know the little royal!

For streaming video from outside the hospital and all the latest updates visit our royal baby live blog.