They are called Cumberland Jacks, and were made to poke fun at the then Duke of Cumberland, who no one liked, and everyone wanted to send him to Hannover. I stole this from the www24carat.co.uk website: Many brass imitations were made as publicity tokens or propaganda pieces. One very common example is the "Cumberland Jack", a brass imitation guinea issued around the time of Queen Victoria's accession in 1837. It features a young head portrait of Victoria on the obverse, and a mounted Duke of Cumberland, after the style of Pistrucci's famous Saint George and Dragon, on the reverse, with the inscription "To Hanover". This was a reference to the Duke, an unpopular character, becoming the ruler of Hanover, a title which Victoria was debarred from inheriting because she was female.