LONDON -- Palace officials say Prince William and his wife are expecting their first child.

St. James Palace said Monday that the Duchess of Cambridge has a severe form of morning sickness and is currently in a London hospital.

As the first born to William - who is second in line to the throne after his father, Prince Charles - the couple's first child stands an excellent chance of one day becoming monarch.

Whether boy or girl, the child will be behind Prince William in the line of succession to the throne, Cabinet Office officials said.