Prince William has had a busy year.

The Duke of Cambridge celebrated his first anniversary with Catherine Middleton and toasted Queen Elizabeth II's Diamond Jubilee. And on Thursday, he adds another milestone to his list: his 30th birthday.

He's now also legally entitled to half of his mother's inheritance, which was left to him after Princess Diana was killed in a car crash in 1997. His half of the inheritance, according to The Daily Telegraph, would likely be around $15.5 million, with the current currency exchange rate. (What William can buy with that chunk of change)

William has been in the spotlight as the eventual heir to the British throne since early childhood. He's endured his parents' breakup, his mother's death and his own big royal wedding all while the world watched along with him.

The Duke of Cambridge has recently said he and his wife are excited about the prospect of bringing a child into the world.

“I’m just very keen to have a family, and both Catherine and I, you know, are looking forward to having a family in the future," he told ABC's Katie Couric before the Diamond Jubilee.

To celebrate William's big day, we wanted to take a look back at his life. After all, many people would say that he and Catherine have helped the royal family become popular again by making the monarchy more accessible to the public.

Click through the gallery above to see William's evolution from Diana and Charles' lovable young son to the Duke of Cambridge.

More on Prince William:

How William, Kate and Harry made royals cool 

Prince William: Diana would have loved Catherine 

Royal wedding: From sunrise to sunset