21 JUNE 2005

Prince William and his father Charles have both been indulging in a bit of high-octane fun. Wills, who turns 23 today, arrived at Cirencester Park Polo Club on a powerful motorcycle, while the heir to the throne made his entrance, along with new wife Camilla, in a classic Aston Martin convertible.

The birthday boy's passion for motorcycles has raised a few eyebrows in royal circles, but he is obviously taking care to avoid any unnecessary risks. The royal biker was cruising along at a leisurely pace, despite the fact his Daytona 600 can accelerate as fast as a Ferrari, and he was wearing a protective jacket, gloves and boots.

William will be donning rather more conservative attire on Thursday when he graduates from St Andrews University, though. The second in line will be sporting a black graduation gown with a traditional black and cherry hood as he receives his degree from the institution's chancellor Sir Kenneth Dover.

And his summer looks set to get off to a storming start because he jets out to New Zealand next week to join the British Lions rugby team. The trip will also see him carrying out his first solo engagements, as he represents the Queen at memorial services in Wellington and Auckland.

"As a huge rugby fan, I cannot think of a better place to watch what will hopefully be a hard-fought and exciting Test series," said the Prince. "But I am also very much looking forward to meeting people outside of rugby and enjoying some of the breathtaking scenery for which New Zealand is so justly renowned."