London, Apr 23 (AP/UNB)  — The youngest child of Britain's Prince William and his wife, Kate, is about to celebrate his first birthday.

Prince Louis will mark the milestone on Tuesday.

He is fifth in line to the throne, behind his grandfather, Prince Charles, his father, Prince William, his brother, Prince George, and his sister, Princess Charlotte.

Louis is a great-grandson of Queen Elizabeth II, who turned 93 on Sunday.

He has largely been kept out of the public eye since he was born.