The first mural of its kind appeared in 1997: A teddy bear lobbing a Molotov cocktail at three policemen in riot gear.
No one could have predicted the explosive impact on the art world of the graffiti, called Mild, Mild West, painted on a brick wall in a working-class Bristol neighbourhood.
But 20 years later, its creator is regarded as the most successful political graffiti artist ever even though few know for sure who he is. Now Banksy - or at least an exhibition featuring 80 original works by the unknown artist - is coming to Auckland.
The Art of Banksy opens at the Aotea Centre in January after shows in Melbourne, Amsterdam, Istanbul and Tel Aviv.
Curated by Banksy's former manager Steve Lazarides, it includes famous paintings such as Girl and Balloon and the controversial work Laugh Now - a graffiti piece that depicts a monkey with a sign hanging from his neck with the words: "Laugh now, but one day we'll be in charge."
Besides his satirical art and subversive messages, Banksy's popularity has been fuelled by the fact his identity - if indeed it is he - remains unknown. This is despite two-decades of attention-grabbing art appearing on dozens of sites throughout the world, opening The Walled Off Hotel in Bethlehem, making an Academy-Award nominated documentary and pulling off a number of "pranks" against the art establishment.
These include secretly hanging his works inside various museums around the world, such as the Museum of Modern Art, the Tate Britain museum, the Metropolitan Museum of Art, the Brooklyn Museum, and the American Museum of Natural History.
Some say Banksy is Bristol painter Robin Gunningham; others attribute his work to Robert Del Naia, frontman of the band Massive Attack, while there's another theory that Banksy is actually a team of seven artists.
The urban legend goes that he adopted his unique stencil technique when, while hiding from police behind a garbage can, he noticed the graffiti imprint of the can's serial number.
Working with stencils is considered fast and the large number of his works on the streets of Bristol, in southwest England, cemented his place in the underground art movement that developed in the area at the end of the 1980s. Aside from paintings, the art now includes sculptures and special displays.
The official reason given for not revealing the identity was that graffiti is illegal but now Lazarides believes even in Banksy did out himself, no one would believe him.
"I encouraged him to do it ten years ago," says Lazarides, "but here was a kid who didn't want to be famous, didn't want to be in the limelight and didn't want to hang out with 'celebrities' which makes him a very rare beast indeed."
This year's Paradox Street Art Festival in Tauranga, with 22 works by Banksy, brought an estimated 10,170 visitors to the city and injected $1.2 million of visitor spending into the region.
For Tauranga District Council, which put $115,000 into the festival, the return of investment was a staggering 293 per cent. There are now also eight large murals on high-profile walls in the city centre, produced by top NZ street artists as part of the festival.
Auckland mayor Phil Goff describes The Art of Banksy coming to the Aotea Centre as a huge win for the city and another example of its growth as an arts and culture destination for locals and visitors.
All the works in it are held by private collectors who get their art back once the exhibition ends in Auckland. Lazarides said the chances that these pieces would ever be displayed together again were extremely slim.
The Art of Banksy is at Auckland's Aotea Centre from January 5 to February 6, including Auckland Anniversary Day and Waitangi Day. Tickets are now on sale for $30; after Christmas prices rise to $35.