These were a series of attacks on Anglican bishops by a Puritan man who emerged as "Martin Marprelate, gentleman" in England around the 1580's. The printing press was being realised as "an engine in the warfare of opinion"1 at this stage and pamphlets were being issued that damned (more like ridiculed) the activities of the Anglican bishops. These attacks lost the Puritan cause large amounts of support because of their savageness.
The first of these attacks was The Epistle. This concentrated on making a mockery of private events in certain Bishop's lives - most of these were exaggerated and blown out of proportion, many didn't even deserve a mention. Scandal was not only created, but created with passion, for Whitgift of Canterbury, Aylmer of London and Cooper of Winchester as these bishops showed the greatest opposition to Puritanism. It also paid special attention to grievances of some Puritans. Penry, Waldegrave and Udall were the main Puritans that were mentioned.
The second, The Epitome, is believed to largely be aimed at Bridges, as promised in The Epistle. In truth, however, it is more aimed at Aylmer of London as he was regarded a turncoat by the Puritans. This tract is pretty similar to the first one but it lapses into a more serious style.
The bishop of Winchester ended up fuelling the fire by responding to Martin with his publication of Admonition to the People of England - this was, of course, responded to with new arguments spurned from its content, The Minerall Conclusions and Hay any worke for Cooper?.
There were a couple more minor tracts after this, but as it took such a long time to accomplish printing and distributing each of them, Martin was an old man by the stage of these later tracts. Martin Junior and Martin Senior both get published and finally the catholic bishops shut Martin up by seizing the press and arresting his printers.
The Marprelate Tracts offended many Puritans as well as catholics and caused some of them to revert back to general Protestantism.