Not much is known about this elusive artist, but Signal Gallery did have this to say:

"SPQR is an artist from the West of England whose work has the ability to take the challenge of Banksy head on and produce a body of mostly stencil based artwork which has it’s own brand of ‘humour through protest’. Unlike Banksy, he has not been interested in developing hype and PR frenzy. In fact, he has actively avoided ‘selling out’ to the more commercial and cynical end of the Street Art movement."