Prince William, Prince George, Princess Charlotte

David Fisher/REX/Shutterstock

Prince George is a big brother once again!

The future King of England has a new little sibling to watch out for, a baby brother this time! George's parents, Prince William and Kate Middleton welcomed their third child on Monday morning.

Prince George and Princess Charlotte were spotted arriving at the hospital on Monday afternoon to meet their new brother. And now that the family has welcomed a new member, we're taking a trip down memory lane to George's earliest years.

The Duke and Duchess of Cambridge's eldest child, who was born on July 22, 2013, will celebrate his fifth birthday in July. But before that, let's look back at the adorable boy's baby pics!

Prince William, Kate Middleton, Princess Charlotte, Prince George, Prince Louis, Family Portrait

Matt Porteous/PA Wire

Prince George, Princess Eugenie Royal Wedding

PA Wire

Prince Charles, Camilla, Prince Willliam, Kate Middleton, Prince George, Princess Charlotte, Prince Louis, Prince Harry, Meghan Markle

Chris Jackson / Clarence House via Getty Images

Prince George, 5th birthday

Matt Porteous/Kensington Palace/Twitter

Prince Louis Christening, Prince William, Prince George, Princess Charlotte

Dominic Lipinski/Pool Photo via AP

Prince George, Savannah Phillips, Princess Charlotte

Max Mumby/Indigo/Getty Images

Kate Middleton, Prince William, Princess Charlotte, Savannah Phillips, Prince George

Karwai Tang/WireImage

Prince George, Royal Wedding

Brian Lawless/PA Wire

Prince George, Fourth Birthday Portrait

Chris Jackson, Getty Images

Prince William, Prince George, Princess Charlotte

David Fisher/REX/Shutterstock

Prince William, Kate Middleton, Prince George, Princess Charlotte, Royal Christmas Card 2017

Chris Jackson/Kensington Palace/Getty Images

Prince George, Prince William, Thomas's Battersea

Richard Pohle/The Times/PA Wire

Prince George of Cambridge

Chris Jackson/Getty Images

Prince George, Royals Gift Guide

Pete Souza/The White House via Getty Images

Prince George, Trooping the Colour 2017

Chris Jackson/Getty Images

Kate Middleton, Princess Charlotte, Prince George, Pippa Middleton and James Matthews Wedding

Kirsty Wigglesworth - Pool/Getty Images

Prince George

Chris Jackson - Pool/Getty Images

Prince William, Prince George, Princess Charlotte, Kate Middleton, Canada

Stephen Lock - Pool/Getty Images

Kate Middleton, Duchess of Cambridge, Princess Charlotte, Prince George

Mark Cuthbert/UK Press via Getty Images

Prince George, Catherine, Duchess of Cambridge, Kate Middleton, Prince William

Chris Jackson/Getty Images

Queen Elizabeth, Prince George, Prince William, Royal Mail Stamps

Ranald Mackechnie / Kensington Palace

ESC: Prince George

Kensington Palace

Kate Middleton, Prince William, Prince George, Princess Charlotte

JOHN STILLWELL/AFP/Getty Images

Kate Middleton, Prince William, Prince George, Princess Charlotte

JOHN STILLWELL/AFP/Getty Images

 Queen Elizabeth II, Royals, Prince George, Prince William, Ducess of Cambridge, Catherine, Trooping of the Colour

AP Photo/Tim Ireland

Prince George, 3rd Birthday

PA Images/Sipa USA

Prince George, Catherine Duchess of Cambridge, Kate Middleton

Rupert Hartley/REX USA

Prince George of Cambridge

Max Mumby/Indigo/Getty Images

Princess Charlotte, Prince George, Duchess Catherine, Prince William

HRH Duchess of Cambridge

Prince George, Catherine Duchess of Cambridge

Chris Jackson/Getty Images

Prince George, Catherine Duchess of Cambridge

Rupert Hartley/REX USA

Princess Charlotte, Prince George, Duchess Catherine, Prince William

HRH Duchess of Cambridge

Prince George, Faces

Chris Jackson/Getty Images

Prince George, Prince William, Kate Middleton

John Stillwell/PA Wire/Press Association via AP Images

Prince William, Duke of Cambridge, Prince George

Chris Jackson/Getty Images

Prince George, Kate Middleton, Prince William

John Stillwell/PA Wire

Prince George

TRH The Duke and Duchess of Cambridge/PA Wire

Prince George

The Duchess of Cambridge

Duchess Catherine, Prince William, Prince George, Kate Middleton

Anthony Devlin/PA Wire/Press Association via AP Images

Prince William, Kate Middleton, Prince George

Chris Jackson/Getty Images

Prince George of Cambridge, Duchess Catherine, Kate Middleton

James Whatling-Pool/Getty Images

Kate Middleton, Prince William, Prince George

Ryan Pierse/Getty Images

Prince George, Official Portrait

John Stillwell/Press Association

Catherine Duchess of Cambridge, Kate Middleton, Prince George

© i-Images, PacificCoastNews.

Kate Middleton, Duchess of Cambridge, Prince William, Prince George

Chris Jackson/Getty Images

Kate Middleton, Duchess of Cambridge, Prince William, Prince George

Chris Jackson/Getty Images

Prince George, Kate Middleton, Prince William

Getty Images

Prince George of Cambridge

James Whatling-Pool/Getty Images

Photos

See More From Prince George's Cutest Photos

The royal baby's name has yet to be announced! Let us know what you think the couple will name their baby boy in the comments!

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