Happy Birthday, Prince William!

The future monarch of the United Kingdom, formally known since his wedding as the Duke of Cambridge, turns 30 on Thursday, and he's about to be a lot richer -- to the tune of 10 million pounds, which is the equivalent of $15.7 million, according to an Associated Press report.

The money is an inheritance from his late mother, Princess Diana. Her estate was set up in a trust after her death. Prince William and his younger brother, Prince Harry, are each entitled to half of it, according to a report in the Telegraph. She left £12,966,022 after taxes, which the Telegraph estimates has grown to approximately £20 million because of investment returns.

The two royals were originally scheduled to inherit the money when they turned 25, but executors changed the age to 30 after their mother died, according to Hello! magazine. At 27, the younger prince has to wait a while longer for his own inheritance.

So how will the heir to the throne celebrate the big 3-0?

Don't expect a big birthday bash. The Telegraph reported that the prince will have a low-key celebration with his friends and wife, the Duchess of Cambridge (aka Kate Middleton).

And don't expect him to blow all of that money in one place, either.

Whatever the financial position might be, you will see no obvious change of lifestyle over the coming weeks or months, a royal aide told the Telegraph. There has been speculation about the Duke and Duchess having a house built but there are no plans for that at all. If the Duke decides next year to continue his Search and Rescue career he might well have to move to another base, away from Anglesey, so the idea of a new house just isn't on the radar at the moment.

Hmm, a new home for him and the missus would be nice. They currently reside in a house in Anglesey, an island off of the coast of Wales. They've been photographed in the area with their dog, Lupo.

Royal watchers, however, are keeping their eyes peeled for an even bigger development: a baby.

The Duke and Duchess are both 30, so the timing would be great. But there hasn't been a sign of a bun in the oven just yet. Royal watchers insist that if the Duchess were pregnant, an announcement would not be made until the three-month mark, although we're thinking the information would leak before then. Surely, a baby bump would be easy to spot on the Duchess' slim figure.

An incident back in November certainly set off a firestorm of pregnancy speculation.

The couple was on royal business in Copenhagen, Denmark when the Duchess declined to sample Plumpy'nut, a peanut paste UNICEF distributes to malnourished children. Photos show that her husband partook of a sample, and Kate's reason for refusing it remains a mystery. It certainly seems if this were some indication of an upcoming bundle of joy, we would have known about it by now. Guess we will just have to wait.

Baby hopes aside, we wish the Duke of Cambridge a big Happy Birthday!