Prince William and Princess Kate have made the birth of their third child, Prince Louis, official.

“The Duke and Duchess of Cambridge have formally registered the birth of Prince Louis,” Kensington Palace said in a statement. “The Duke of Cambridge signed the birth register at Kensington Palace this morning, witnessed by a Registrar from Westminster Register Office.”

PHOTO: Prince William and Kate depart the hospital with the new baby boy at the Lindo Wing in St Mary's Hospital, April 23, 2018, in London.
Ian Jones/Allpix/Splash News
Prince William and Kate depart the hospital with the new baby boy at the Lindo Wing in St Mary's Hospital, April 23, 2018, in London.

As was seen on the birth register entries of their older children, Prince George and Princes Charlotte, William and Kate's occupations are listed on the document as Prince of the United Kingdom and Princess of the United Kingdom, respectively.

PHOTO: The official birth register entry of Prince Louis Arthur Charles of Cambridge, infant son to Prince William and Kate the Duchess of Cambridge, as the document is made available to the media in London, May 1, 2018.
Dominic Lipinski/AP
The official birth register entry of Prince Louis Arthur Charles of Cambridge, infant son to Prince William and Kate the Duchess of Cambridge, as the document is made available to the media in London, May 1, 2018.

Prince Louis Arthur Charles was born at 11:01 a.m., local time on April 23.

The baby, known as His Royal Highness Prince Louis of Cambridge, made his first public appearance just seven hours after his birth outside St. Mary’s Hospital in London.

William, 35, and Kate, 36, traveled from the hospital to Kensington Palace, where they have been bonding as a family of five, including all three children: Newborn Louis, George, 4, and Charlotte, who turns 3 on Wednesday.

PHOTO: Prince William and Catherine Duchess of Cambridge leave the hospital with their newborn baby boy at the Lindo Wing, St Mary's Hospital, London, April 23, 2018.
Hannah Mckay/Reuters
Prince William and Catherine Duchess of Cambridge leave the hospital with their newborn baby boy at the Lindo Wing, St Mary's Hospital, London, April 23, 2018.

Kate will take some time off from official royal engagements, as she did after the births of George and Charlotte.

Princess Charlotte of Cambridge, Prince George of Cambridge by their father Britain's Prince William, Duke of Cambridge, at the Lindo Wing of St Mary's Hospital in London, April 23, 2018, to visit Catherine, Duchess of Cambridge, and their new-born son.
Ben Stansll/AFP/Getty Images
Princess Charlotte of Cambridge turns to wave at the media as she is lead in with her brother Prince George of Cambridge by their father Britain's Prince William, Duke of Cambridge, at the Lindo Wing of St Mary's Hospital in central London, April 23, 2018, to visit Catherine, Duchess of Cambridge, and their new-born son.

The Duchess of Cambridge is still expected to attend Prince Harry's wedding to Meghan Markle on May 19. She is also expected to join the royal family at Trooping the Colour in June.

William, the Duke of Cambridge, is currently taking some time off to spend with his family following Louis's birth. He has attended two royal engagements since the birth. But, as a father actively engaged in the upbringing of his children, he is hoping to enjoy the precious moments of joy after the birth of a new child.

PHOTO: Prince William and Catherine Duchess of Cambridge leave the hospital with their newborn baby boy  at the Lindo Wing, St Mary's Hospital, London, April 23, 2018.
Tim Rooke/REX via Shutterstock
Prince William and Catherine Duchess of Cambridge leave the hospital with their newborn baby boy at the Lindo Wing, St Mary's Hospital, London, April 23, 2018.

With George and Charlotte both currently attending school near Kensington Palace -- George at Thomas's Battersea and Charlotte at the Willcocks Nursery School -- Kate and William are expected to enjoy some solo time with their new infant at the palace.

The family may then decamp to Anmer Hall -- their 10-bedroom home on the queen’s Sandringham Estate in Norfolk, England -- for added privacy.