Mild Mild West was painted in 1999.
It's believed that this Banksy piece is influenced by the Bristol riots that took place in the early 1980's. The truth is however that it has very little to do with that. In the book "Home Sweet Home" written by Jim Paine, Paine talks about the violent methods that police were using to break up "rave" nights in warehouses across the city. At one unlicensed event at Winterstoke Road, Bristol “Many of the crowd that night were assaulted by police…it marked the beginning of a more hardline approach from the police, using violence as a method of breaking up parties."
It took Banksy three days to paint this piece. He done in broad daylight and has long become one of the most iconic pieces of streetart in Bristol so much so that it is even feature on the Visit Bristol website.
In 2009 the piece was vandalised by Appropriate Media. The anti-graffiti group thought it was a good idea to protest Banksy's "vandalism" by vandalising it with red paint. The irony was obviously lost on the group. Bristol City Council quickly repaired it though and started to put plans in place to encase the piece in Perspex to protect it. Many Banksy works have been protected this way.
Have a closer look in here