News that Britain's Prince William and his wife Kate will be having a baby have got people around the world in a tizzy.

Mainstream media and showbiz websites went into overdrive after the announcement, providing updates on the Duchess of Cambridge's extreme morning sickness and what it means for the monarchy.

The baby, whether a he or she, will be third in line to the throne, after Prince Charles and Prince William.

The royal baby will be the latest addition to a very privileged group of children who carry the titles of 'prince' and 'princess' and are destined to be future kings and queens.

These include the daughter of Sweden's Crown Princess Victoria, who was born on Feb 23 this year and is second in line to the throne.

According to the new British succession laws, which were amended last year, Prince Wiliam's first-born child will leap-frog over Prince Harry in the succession line to the throne, regardless of whether it is a girl or boy.

Here is a look at other royal children around the world who are born to be kings and queens.

(Photos: Reuters, AFP)