If you haven’t come across Orlando the Gap Yah student, then get on to YouTube and join the four million plus viewers who have nearly wet themselves laughing. Based on the characters he met while at Oxford (yah!), Matt Lacey is now cashing in on his newfound fame with The Gap Yah Plannah. Swinging into town to sign copies and meet his legions of new fans, Katherine MacAlister gets to Orlando first.

Matt Lacey was queueing for the Zodiac on Cowley Road, when he heard the immortal words which would change his life for ever.

“I was surrounded by more than the usual number of gilets and Jack Wills tops when suddenly all the girls started squealing: ‘Tarquin’s chundered everywhere’,” Matt says.

“But until I got to Oxford I had no idea that people like that even existed, let alone in such large numbers.” The ‘people like that’ provided Matt with enough ammunition to base his sketch show on, and when he posted it online, Orlando went global.

There’s now a Gap Yah T-shirt, single, book, Wikipedia entry and tour, or in Orlando’s words: “world famous travel expert returns to his spiritual Mothership Oxford yah to meet the cream of Britain’s young and privileged and ask why they are wasting Mater and Pater’s money on university when they could be splashing it on a massive jolly jaunt abroad yah!”

Orlando is here to stay and Matt is hanging on to his coat tails for dear life.

“I hardly realised myself how hilarious Orlando was, so it’s nothing to do with me.

“Because Orlando is actually based on a friend-of-a-friend, and when I first met him I thought his name was Miranda because he said it in such a posh voice,” Matt laughs.

“And the funny thing is I was sent Orlando’s real gap year diaries and several of the imaginary incidents I’d written about in the book actually happened! But Orlando the character all started as a voice I put on to take the mick out of a friend of mine for being a bit posh and slowly evolved through the people I met.”

Matt, 25, studied history at Oxford (his thesis was based on an obscure Irish moustache law), but unsurprisingly was always drawn to the stage. He joined the Oxford Review, performed at the Old Fire Station, and formed The Unexpected Items when they left, who were still definitely fringe until Orlando was born.

“We’d been performing the Gap Yah sketch on stage for the past two years, and thought it would be worth filming and posting online. One Friday we had 40,000 hits and it just went mad. So YouTube was the perfect vehicle at the perfect time.”

Orlando is now so popular he was named ‘The most popular Sloane since Princess Diana’ by BBC News and is being watched by people all over the world.

So does Matt feel like he’s had the last laugh? “Well no, because even when the real Orlando is talking he’s totally unaware of himself. So while I did make up some of the language like ‘vomcano’ and ‘lashmina’, other words like chunder are the words they use, they have a very specific language.”

Matt had a gap year and went to Oxford, so isn’t he just a Sloane in denial? “Most of my gap year was spent in Ireland working in a Chinese restaurant run by Romanians and I live in Hoxton now, which isn’t really Orlando’s playground.”

Orlando will be signing copies of his book The Gap Yah Plannah on Saturday at Waterstones, Oxford, at 2.30pm. Call 01865 790212 for details or see waterstones.com