Kate Middleton, Prince William and Prince Harry Watch in Dismay as Mark Cavendish Crashes Out of Tour De France

The look on Kate Middleton's face said it all as Mark Cavendish collided into fellow cyclist Simon Gerrans in the first leg of the Tour De France.

The cycling champion, who was bidding for the 26th Tour stage win of his career and a first yellow jersey, crashed to the ground just 350 metres from the finish.

Showing his determination and resolve, he climbed back on his bike and rolled over the finish line before being taken to Harrogate District Hospital for treatment for a suspected broken collar bone in the fall.

With the future of the Tour now in doubt for the British hopeful, he said he was "gutted."

"I'm gutted about the crash today. It was my fault. I'll personally apologise to Simon Gerrans as soon as I get the chance. In reality, I tried to find a gap that wasn't really there.

"I wanted to win today, I felt really strong and was in a great position to contest the sprint thanks to the unbelievable efforts of my team. Sorry to all the fans that came out to support - it was truly incredible," he added.

The Duchess of Cambridge was joined by Prince William and Prince Harry at the starting line, as she officially opened the world's biggest annual sporting event at Harewood House, near Leeds.

Recycling the vibrant green Erdem coat-dress she wore during her tour of Australia, Kate cut the ribbon for the Grand Depart, where more than one million cycling fans lined the streets for the historic opening stag.

Before the race began, all 198 riders lined up in the centre of Leeds, where they were welcomed with a rendition of both the French and British national anthems, performed by the Band of the Corps of the Royal Engineers.

The crowd erupted into cheers as the RAF's Red Arrows performed a flyover that left a trail of red, white and blue vapour - the national colours of France and the UK.

Prince William, Prince Harry and Kate chatted with the lead riders, including reigning Tour champion Chris Froome.

After Cavendish crashed out, Germany's Marcel Kittel raced away to win the opening stage of the Tour for a second year running.

Kate presented the coveted yellow jersey to Kittel, at the end of the opening leg of the race.