Lollardy, a form of anti-clerical proto-protestantism preached largely by Oxford academics in particular John Wycliffe, was perceived as a threat to the rule of the Crown and of the Church. In common with later protestantism the Lollards believed that the Roman Catholic Church was perverted, iconoclasm and began to translate the Bible into the vernacular. Persecution began in 1381 with the Peasant's revolt yet it was King Henry IV's Act De haeretico comburendo of 1401 that heralded the beginning of a hundred years of herectics executions.
Editors. "Lollard reformers persecuted in England". The Literary Encyclopedia. First published 01 March 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=9572, accessed 23 February 2017.]