One of the most well known political figures in late 18th century England was a political radical (and radical Protestant) called Lord George Gordon, 1751-1793 (according to Wikipedia, his father was named Cosmo George Gordon. No, you can't make this stuff up!). In July of 1780 he led a crowd of 50,000 people in a protest march to the House of Commons and a riot broke out for five days, for which he was held responsible by the law. He eventually served five years in prison, but not before converting to Judaism, which is a whole 'nuther story.
There is a popular book for children about him:
He appeared in court on January 28, 1793. Here is the Times' account of it the next day. It is well worth reading (just click the images to make them bigger if need be):
In prison caricature, from David B. Ruderman's 'Jewish Enlightenment in an English Key'):
And another one, from 1780: