New aunt and uncle, Prince William and Kate Middleton, have gushed over the birth of the new royal baby who they have yet to meet.
On Monday, Prince Harry and Meghan Markle welcomed their first child into the world, ending weeks of speculation about when the birth may take place or if the baby had already been delivered.
A statement released after the birth said immediate members of the royal family had been informed and were delighted with the news.
Prince William and Kate spoke to reporters on Tuesday (local time) about their excitement about becoming aunt and uncle and whether they had advice for the parents.
"Absolutely thrilled. Looking forward to seeing them in the next few days when things have quietened down," Prince William said.
"I'm very pleased and glad to welcome my own brother into the sleep deprivation society that is parenting."
With three royal children of his own, the Prince said he has lots of advice for the new parents, but hopes they can try to relax and take it all in.
"There is plenty of advice, but I wish him all the best and I hope over the next few days they can settle down and enjoy having a newborn in their family and the joys that with that."
Kate said it will be a "special time" for the Duke and Duchess of Sussex, and noted that with Princess Charlotte and Prince Louis recently having their birthdays, it was a good time to have a baby.
Celebrities and politicians like Michelle Obama, Ellen DeGeneres and Theresa May have all sent Prince Harry and Meghan their congratulations.
The baby boy is seventh in line to the throne, following the Prince of Wales, the Duke of Cambridge and his children, and then Prince Harry.