Oldcastle Revolt religious beliefs were considerably influenced by Lollard cleric William Swynderby, who preached in Almeley during his youth. Lollardy was a politico-religious movement initiated by prominent theologian John Wycliffe in the 1370s during his service in the University of Oxford. Lollard beliefs were outlined in the 1395 The Twelve Conclusions of the Lollards, which dealt with their opposition to capital punishment, rejection of religious celibacy, and belief that members of the Clergy should be held accountable to civil laws. The Conclusions also rejected pilgrimages, ornamentation of churches, and religious images because these were said to take away from the true nature
John Wycliffe that Wycliffe was targeted by John of Gaunt's opponents among the nobles and church hierarchy. Gaunt, the Earl Marshal Henry Percy, and a number of other supporters accompanied Wycliffe. A crowd gathered at the church, and at the entrance, party animosities began to show, especially in an angry exchange between the bishop and Wycliffe's protectors. Gaunt declared that he would humble the pride of the English clergy and their partisans, hinting at the intent to secularise the possessions of the Church. The assembly broke up and Gaunt and his partisans departed with their protégé. Most of the English clergy were