There's a royal baby on the way.
Palace officials announced Monday that Prince William and Kate are expecting their first child.
"Their Royal Highnesses The Duke and Duchess of Cambridge are very pleased to announce that The Duchess of Cambridge is expecting a baby," the announcement said. "The Queen, The Duke of Edinburgh, The Prince of Wales, The Duchess of Cornwall and Prince Harry and members of both families are delighted with the news."
The announcement added that Kate was admitted to King Edward VII Hospital in London on Monday with a severe form of morning sickness. William is at his wife's side.
News of the pregnancy drew congratulations from across the world, with the hashtag "royalbaby" trending globally on Twitter.
The couple's first child will be third in line to take the throne - leapfrogging the gregarious Prince Harry and possibly setting up the first scenario in which a U.K. female heir could benefit from new gender rules about succession.
The palace would not say how far along the 30-year-old duchess is, only that she has not yet reached the 12-week mark. Palace officials said the duchess was hospitalized with hyperemesis gravidarum, a potentially dangerous type of morning sickness where vomiting is so severe no food or liquid can be kept down. They said she was expected to remain hospitalized for several days and would require a period of rest afterward.
In recent days, Kate has kept up royal appearances -- recentlywith schoolchildren at her former prep school and with her husband.
The confirmation of her pregnancy caps a jam-packed year of highs and lows for the young royals, who were married in a lavish ceremony at Westminster Abbey last year.
They have traveled the world extensively as part of Queen Elizabeth II's Diamond Jubilee celebrations and weathered the embarrassment of a nude photo scandal, after a tabloid snapper published topless images of the duchess.
Joe Little, managing editor of Majesty magazine, said the news bookended a year that saw the royal family riding high in popular esteem after celebrations of Queen Elizabeth II's 60 years on the throne.
"We're riding on a royal high at the moment at the end of the diamond jubilee year," he said. "People enjoyed the royal romance last year and now there's this. It's just a good news story amid all the doom and gloom."
Speculation about when William and his bride would start a family has been rife since their wedding.
William's mother -- the late Princess Diana -- got pregnant just four months after her wedding in 1981. Like Kate, Diana reportedly suffered from morning sickness for months and complained of constant media attention.
"The whole world is watching my stomach," Diana once said.
American tabloid speculation of the pregnancy has been rampant for months. One newspaper even cited anonymous sources talking about Kate's hormone levels. Others have focused on the first signs of the royal bump.
News of the pregnancy drew congratulations from across the U.K. establishment. The palace said the royal family was "delighted" by the news, while Prime Minister David Cameron wrote on Twitter that the royals "will make wonderful parents."
Not only are the attractive young couple popular -- with William's easy common touch reminding many of his mother -- but their child is expected to play an important role in British national life for decades to come.
Whether boy or girl, the child will be behind William in the line of succession to the throne, Cabinet Office officials said.
Leaders of Britain and the 15 former colonies that have the monarch as their head of state agreed in 2011 to new rules which give females equal status with males in the order of succession.
Although none of the nations had legislated to make the change as of September 2012, the British Cabinet Office confirmed that this is now the de-facto rule.
On the couple's tour of Malaysia, Singapore, the Solomon Islands and Tuvalu in September, William reportedly said he hoped he and Kate would have two children.