A beaming Prince Harry said his wife Meghan gave birth to a baby boy early Monday morning.
Harry says he's "incredibly proud" of his wife and that they have a healthy baby boy who weighs 7 pounds 3 ounces. He has not yet been named.
Harry said the child was a little bit overdue and that had given them more time to contemplate names. He says he is ecstatic about the birth of their first child and said more details will be shared in the coming days.
"This little baby is absolutely to die for," he said. "I'm just over the moon."
The infant will be seventh in line to the British throne and Queen Elizabeth II's eighth great-grandchild. Harry is the younger son of Prince Charles, the next in line to the throne, and the late Princess Diana, who died in a Paris car crash in 1997.
The child will be eligible for dual British-U.S. citizenship if Meghan and Harry want to go through the application process.
Harry, speaking before TV cameras on Monday afternoon was present for the birth, which he said was an amazing experience. The couple has said they didn't find out the baby's sex in advance.
Senior royals have been informed of the birth, as has the family of Princess Diana, Harry's late mother.
Meghan, the Duchess of Sussex, was formerly known as Meghan Markle and was a TV star before retiring from acting to marry Harry at St. George's Chapel on the grounds of Windsor Castle a year ago.
Journalists and well-wishers have camped out for days in Windsor, about 35 kilometres (22 miles) west of London, awaiting the baby's arrival.
Meghan, a California native, had a starring role on the American TV series "Suits." She had a previous marriage that ended in divorce and has strong feminist views. As the daughter of a black mother and a white father, she says she identifies as biracial.
Harry, who has said he wanted to protect his wife from intrusive media coverage, and Meghan have said they plan to keep many of the details of the birth private.
The birth marks the completion of Harry's transformation from troubled teenager to committed military man to proud father. He has long spoken of his desire to start a family.
He and his older brother, Prince William, along with their wives, are seen by many in Britain as the new, fresh face of a royal family that had become stodgy and aged. They are raising the next generation of royals amid a genuine groundswell of public support for the monarchy.
Meghan in particular represents a change for the royals: She is American, older than her husband, divorced, and comes from a biracial background.
She also achieved considerable success in her own right before agreeing to a blind date with Harry that changed both their lives. Meghan had an important role in the popular TV series "Suits" and had a wide following even before she joined the world's most famous royal family.
Harry and Meghan recently moved from central London to a secluded house known as Frogmore Cottage near Windsor Castle, 25 miles (40 kilometres) west of London. The move is seen in part as reflecting a desire for privacy as they raise their first child.
It also separates Harry and Meghan from William and his wife Kate, the Duchess of Cambridge, who had been living in the same compound at Kensington Palace in central London.