LONDON Get the nursery ready: Prince William and his wife Kate are expecting their first child.
St. James's Palace announced the pregnancy Monday, saying that the Duchess of Cambridge formerly known as Kate Middleton has a severe form of morning sickness and is currently in a London hospital. William is at his wife's side.
The palace said since the pregnancy is in its very early stages, the 30-year-old duchess is expected to stay in the hospital for several days and will require a period of rest afterward.
It would not say how far along she is, only that she has not yet reached the 12-week mark.
News of the pregnancy drew congratulations from across the world, with the hashtag royalbaby trending globally on Twitter.
Not only are the attractive young couple popular with William's easy common touch reminding many of his mother, the late Princess Diana but their child is expected to play an important role in British national life for decades to come.
William is second in line to the throne after his father, Prince Charles, so the couple's first child would normally eventually become a monarch.
In recent days, Middleton has kept up her royal appearances recently playing field hockey with schoolchildren at her former school.
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 photos scandal, after a tabloid 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 the couple 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. 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.
The palace said the royal family was delighted by the news, while British Prime Minister David Cameron wrote on Twitter that the royals will make wonderful parents.
Whether boy or girl, the child will be next in line behind William in the line of succession to the throne, Cabinet Office officials have 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 recent tour of Malaysia, Singapore, the Solomon Islands and Tuvalu in September, William reportedly said he hoped he and Kate would have two children.
Associated Press writers Jill Lawless and Paisley Dodds contributed to this report.