Take a look back at 1 NEWS NOW's live updates on the birth of the Duchess of Cambridge and Prince William's third child:
1 NEWS Europe Correspondent Joy Reid has the latest.
The baby boy arrived just after 11am London time (10pm yesterday NZDT). Weighing eight pounds seven ounces (3.8 kilograms), the new prince is fifth-in-line Royal to the throne and the Queen's sixth great-grandchild.
7.10am: Prime Minister Jacinda Ardern has described the birth as "incredible" and indicated she will be sending a collection of New Zealand books as gifts on TVNZ's Breakfast this morning.
Ms Ardern also touched on the quick public appearance of Kate outside a London hospital just seven hours after giving birth.
"I just want to lower expectations," the Prime Minister said, referencing her own impending due date and the likely recovery period.
6.56am: On the potential names for the new baby, William was tight lipped as he left St Mary's Hospital: "You'll find out sooner or later," he said. Albert, Arthur, Jack and Fred are the bookmakers picks.
6.50am: Outside St Mary's Hospital in west London where his other two children, George and Charlotte, were also born, Prince William spoke briefly to reporters as they left.
"Thrice the worry now," Prince William told the media. "We didn't keep you waiting too long this time. Very happy, very excited, thank you.
Earlier today, leaving hospital: The Duchess of Cambridge and Prince William have left a London hospital and headed home with their newborn son.
The duchess, who gave birth last night (Monday morning UK time), emerged from St. Mary's Hospital about seven hours later alongside her husband, holding the baby wrapped in a white blanket. The trio posed for photographers before going back inside.
The royals emerged a few minutes later with their infant in a carrier and got into a waiting car.
Family visit: The newborn prince's elder siblings, Prince George and Princess Charlotte, already had gone home after a brief first meeting with their baby brother. Royal officials say the baby weighed in at eight pounds, seven ounces (3.8 kilograms). The prince, whose name has not been released, is fifth in line to the British throne.
Prince George and Princess Charlotte have arrived at London's St. Mary's Hospital to meet their new baby brother.
Prince William left the hospital Monday afternoon and returned half an hour later with his two elder children.
George, who is 4, wore the navy blue shorts and sweater of his school uniform, and ignored the waiting media and well-wishers. Charlotte, who is almost 3, gave the crowd a wave as the family entered the hospital's private Lindo Wing.
The Duchess of Cambridge gave birth to an 8-pound, 7-ounce (3.8 kilogram) baby boy on Monday morning. The new baby is fifth in line to the throne, behind his brother and sister.
Prince William has left St. Mary's Hospital five hours after the birth of his third child, promising to return soon — likely with his older children in tow.
William said "back in a minute" as he emerged from the hospital just after 4 p.m. (1500 GMT; 11 a.m. EDT), waved at gathered media and well-wishers and drove off in a waiting Land Rover.
There's expectation he will bring 4-year-old Prince George and Princess Charlotte, who turns 3 next week, to meet their baby brother.
William's wife, the Duchess of Cambridge birth, gave birth to a son just after 11 a.m. (1000 GMT; 6 a.m. EDT) Monday.
Political reaction: British Prime Minister Theresa May has offered "warmest congratulations" to Prince William and the Duchess of Cambridge on the birth of their new son.
May says that "I wish them great happiness for the future."
The couple's Kensington Palace office says Kate gave birth at 11:01 a.m. (1001 GMT; 6:01 a.m. EDT) to a boy weighing 8 pounds, 7 ounces (3.8 kilograms). The baby is the couple's third child and is fifth in line to the throne.
The news brought cheers from dedicated royal-watchers outside London's St. Mary's Hospital, where a self-appointed town crier proclaimed the birth.
The words "it's a boy" were flashed in lights around the top of London's BT Tower, which can be seen for miles around.
Announcement: Kensington Palace says the Duchess of Cambridge has given birth to her third child, a boy weighing 8 pounds, 7 ounces (3.8 kilograms).
The palace says the child was born at 11:01 a.m. (1001 GMT; 6:01 a.m. EDT), a few hours after Kate was admitted to London's St. Mary's Hospital in labor.
Prince William was present for the birth of his son, who is fifth in line to the throne.
The palace says "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."
Kate goes into labour: Kensington Palace says Prince William's wife, the Duchess of Cambridge has entered a London hospital to give birth to the couple's third child.
The former Kate Middleton traveled by car on Monday morning to the private Lindo Wing of St. Mary's Hospital in central London. The palace says she was in "the early stages of labor."
The gender of the baby hasn't been announced.
The couple, who married in 2011, has two other children: Prince George, 4, and two-year-old Princess Charlotte. Both were born at the same hospital, as were William and his younger brother Harry.
SHARE ME