Walk this way: New photo marks Prince George's birthday

The little boy, wearing striped dungaree shorts over a navy blue top, is pictured confidently on his feet with his arms outstretched and his eyes fixed on his destination.

The photograph was taken a few weeks ago at London's Natural History Museum, where the Duke and Duchess of Cambridge took their son to visit the Sensational Butterflies outdoor exhibition.

"Prince George was very lively and very sure of himself and confident -- a very determined young boy," said John Stillwell, a photographer with the Press Association wire service who took the picture.

"When you have children yourself you don't realise they grow up in such a short space of time -- it's always other people saying how big they've grown.

"So having seen him soon after he was born and at his christening three months later, he's now gone from a baby at his christening to a toddler, that's the biggest change.

"And who does he look like? I'd have to say his dad, William."

George has become something of a style icon and his outfit of dungarees by French label Petit Bateau, worn over a polo shirt-style top and with shoes and socks, is likely to be copied around the world.

George, who is third in line to the throne after his grandfather Prince Charles and father Prince William, will spend his birthday at home in Kensington Palace.