The Conventicle Act of 1593 (or Religion Act 1592) stated that anyone over 16 who failed to attend the Parish Church or persuaded others to do the same should. It is the law that was used to put John Bunyan in prison in 1660.
A fresh Conventicle Act was passed in 1664 (part of the Clarendon Code as it was later called). This act forbade religious assemblies of more than five people outside the auspices of the State Church. In his diary the previous September Samuel Pepys quotes his cousin, a barrister and MP, speaking of "too devilish a severe act against conventicles; so beyond all moderation, that he is afeard it will ruin all".
In 1670 a second conventicles act, "An Act to prevent and suppress Seditious Conventicles" was passed legislating fines for attending or facilitating conventicles. This is the act that Andrew Marvell referred to as "the quintessence of arbitrary malice" (in a letter to William Popple).