The conflicts between the secular and religious powers in England during the revolutionary period of 1368-1385 are masterfully explained by G.M. Trevelyan.
Real power in England (King, nobility, Church, Papacy)
The King and his government were powerless to enforce the law or to act against the nobility because their sole military resources were those commanded by the nobles themselves.
The Church was a giant privileged political, judicial and financial powerhouse. Being a part of the Catholic Church, the English Church transferred a big chunk of its revenues abroad (the Papacy, France - in war with England!).
The immorality of the Church
The Church treated sin and fear of Hell as a means of filling her coffers, preying on the vices it was supposed to correct. The sale of pardons and the venality of the confessors were in fact encouragements of sin.
Her enormous real estate wealth was the result of a custom of bequeathing land and/or money to churches and monasteries in order to secure the repetition of masses for the soul of the dead donors.
The Manorial System was based on serfdom. But, the System was undermined by the Black Plague (up to one half of the population died). The farm wages trebled and the serfs fled the manors in order to sell their labor to the highest bidders.
The Peasant's Rising of 1381
The sparkle which ignited the revolt was the levy of poll-taxes (three times in four years). The real causes, however, were the demands for a general charter of liberation of the serfs (complete personal and economic freedom) and the regulation of wages.
On the religious front, the peasants' leaders asked for a disendowment of the Church properties and the abolition of her hierarchy.
After the Rising, all socials concessions were shamelessly withdrawn by the wealthy few.
John Wycliffe supported England against the Papacy and the State against the Church. He accepted the rights of property and the performing of services even for sinful lords.
His main preoccupation, however, was the living conditions of the poor.
He pleaded for the disendowment of all religious properties, hoping that this measure would relieve the pressure of taxation on the poor. His backers within the nobility, however, saw here an opportunity to claim the restitution of the wealth given to the Church by their forebears out of fear of eternal burning. He also proposed to severe the link between the clergy and the State (State offices).
He called the religious regular orders (monks, friars = the Pope's agents for the sale of indulgences) useless and attacked the Transubstantiation theory.
With his impeccable reputation he could impose his moderate view against the call for bloody revenge from the nobility against the peasants after their Revolt.
The spirit of liberty (also of thought) courageously shown by John Wycliffe, as well as the spirit of resistance to tyranny, continued to live among the population. They secured an early abolition of serfdom and feudalism in England.
The struggle against the power of the Church culminated into the changes imposed by Henry VIII.
This book, which reads like a thriller, is q must read for all those interested in English and medieval history. One easily understands why John Wycliffe was considered as a dangerous heretic by the Catholic Church.
N.B. I am not a professional historian. Some commentators consider G. M. Trevelyan as a partisan political (liberal) historian. Corrections on his vision are welcome.