Watch: Britain celebrates as William's wife Kate gives birth to baby boy
Kate, wife of Britain's Prince William, has given birth to a son.
"Her Royal Highness The Duchess of Cambridge was safely delivered of a son at 11:01 (1001 GMT)," Kingston palace said in a statement.
This is the couple's third child after they had a son and daughter earlier.
Prince George was born in 2013 and later Kate gave birth to a girl named Princess Charlotte in 2014.
Fans had gathered outside St. Mary's hospital as they waited for the news about Kate's impending baby.
The betting market was in full swing all day today as the odds swung from girl to boy as the bookmakers favourite for the gender of the third child of the Duke and Duchess of Cambridge, according to Ladbrokes, prior to the birth of the couple's baby boy on Monday.
Arthur and Alice were the most popular names for Britain's fifth in line to the throne - both at 5/1, Ladbrokes said prior to the birth, with the gender being a boy at 10/11.
For a boy, the next most popular names were James at 8/1 and Albert at 12/1.