Royal baby arrives: Duchess Kate gives birth to a boy

It's a boy for Prince William and Kate, Duchess of Cambridge.

The former Kate Middleton gave birth to the couple's first child, a son, on Monday afternoon at a London hospital.

The birth was announced via a formal press release issued by Kensington Palace, which stated that the duchess "was safely delivered of a son" at 4:24 p.m., local time, weighing 8 lbs., 6 oz.

"The Duke of Cambridge was present for the birth," the statement added. "The Queen, The Duke of Edinburgh, The Prince of Wales, The Duchess of Cornwall, Prince Harry and members of both families have been informed and are delighted with the news."

"We could not be happier," Prince William said via a palace spokesperson. He will be spending the night at the hospital with his wife and new baby.Mother and son are both doing well, the palace said, and will remain in the hospital overnight.

A palace source tells CBS News that William was with the duchess throughout her labor, and called the queen, Prince Charles, Prince Harry and the Middletons with the news.