The Plotters
The plot is known also as Watson's Plot, the Catholic Plot, or the Surprising Treason. Another name is "Treason of the Priests". Those involved were not in fact exclusively Catholic priests: Thomas Grey, 15th Baron Grey de Wilton was a Puritan layman who became drawn in, though the plot never went further than far-fetched discussion. Another lay conspirator was Sir Griffin Markham.
Their motivations were varied, while they may have had in common a wish for religious toleration. Watson wished to have no more fines for recusancy levied. Another plank in the platform of the Bye Plot was the removal of certain ministers of the king. To the extent that these matters can be clarified, the Main Plot that had been laid in parallel wished also for regime change, with James replaced on the throne by Arabella Stuart.
Read more about this topic: Bye Plot