Dad Prince William, who is second in line to the throne, has four names — William Arthur Philip Louis.
The newest member of the royal family is fifth in line to the throne, and Queen Elizabeth II’s sixth great-grandchild.
The young family now lives in London’s Kensington Palace, where William and his brother Prince Harry grew up, after residing for several years at their country home in Norfolk, Anmer Hall.
This year is full of momentous occasions for the royals, who will celebrate Harry’s marriage on May 19. In November, Prince Charles, the queen’s son and first-in-line to the throne, will celebrate his 70th birthday.
The queen is scheduled to celebrate another royal birth this summer when she becomes a great-grandmother for a seventh time when Prince William’s cousin Zara Tindall gives birth.