Prince George will soon be an older brother!

Learn 7 Interesting Facts about Prince George

His royal parents, the Duke and Duchess of Cambridge, are expecting baby No. 2. The second baby will be fourth in line to the throne.

"The Duke and Duchess of Cambridge are very pleased to announce that The Duchess of Cambridge is expecting their second child," the royal Twitter account confirmed on Monday. "The Queen and members of both families are delighted with the news that Their Royal Highnesses are expecting their second child."

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Prime Minister of the United Kingdom David Cameron also offered kind words for the couple. "Many congratulations to the Duke and Duchess of Cambridge. I'm delighted by the happy news that they're expecting another baby," he tweeted.

A royal announcement also revealed that The Duchess is being treated for hyperemesis gravidarum by doctors at the Kensington Palace. The 32-year-old suffered from the condition, also known as severe morning sickness, during her first pregnancy. In turn, The Duchess won't accompany her husband, Prince William, to Oxford on Monday as originally planned.

The news comes two months after Prince George celebrated his first birthday on July 22. His proud parents released a statement for their child's milestone.

"We would like to take this opportunity on George's first birthday to thank everyone over the last year, wherever we have met them, both at home and overseas, for their warm and generous good wishes to George and our family," they said at the time.