Britain's Prince William (2nd L), Duke of Cambridge arrives with Prince George (1st L) and Princess Charlotte (2nd R) to visit Britain's Catherine, Duchess of Cambridge, who has given birth to a baby boy at St Mary's Hospital in London, Britain, on April 23, 2018. Princess Kate on Monday gave birth to a boy, her third child, who is the fifth in line to the British throne. (Xinhua/Stephen Chung)
The newborn will join siblings Prince George, 4, and Princess Charlotte, who turns 3 on May 2. He is Queen Elizabeth II's sixth great-grandchild.
Kensington Palace announced Kate's pregnancy in September. Early in her pregnancy Kate suffered from hyperemesis gravidarum, or extreme morning sickness, as she did with her first two pregnancies.
