Short answers, pulled from the story.
Lollardy was initially led by John Wycliffe, a Catholic theologian who was dismissed from the University of Oxford in 1381 for heresy. Wycliffe held that the Bible was the only valid source of doctrine and rejected transubstantiation, arguing that it was philosophically impossible because it required the destruction of matter.
According to the Oxford English Dictionary, Lollard most likely derives from the Middle Dutch lollaerd, meaning "mumbler" or "mutterer", from the verb lollen. It was originally a derogatory nickname for followers of Wycliffe who lacked an academic background. By the mid-15th century it had come to mean a heretic in general.
The Twelve Conclusions were a set of demands posted on the doors of Westminster Hall in February 1395, petitioning Parliament. They covered topics including rejection of clerical wealth, opposition to Church involvement in secular government, condemnation of saint worship as idolatry, and the view that the Eucharist was not clearly defined in scripture.
The law De heretico comburendo, enacted in 1401 during the reign of Henry IV, made heresy equivalent to sedition against the state. John Badby became the first layman executed for heresy in England in 1410. In the Diocese of London, about 310 Lollards were prosecuted or forced to abjure between 1510 and 1532.
John Oldcastle was a close friend of Henry V of England and a committed Lollard. Brought to trial in 1413, he escaped from the Tower of London and organized an insurrection that included an attempted kidnapping of the king. He was subsequently executed. Oldcastle is also the historical basis for the character of Falstaff in Shakespeare's Henry IV, Part 1.
Lollards were effectively absorbed into Protestantism during the English Reformation, though scholars debate whether Protestants directly drew on Lollard ideas or invoked the movement to create a sense of English Protestant tradition. Archbishop Thomas Cranmer referenced Lollardy, and Bishop Cuthbert Tunstall called Lutheranism the "foster-child" of the Wycliffite heresy. The similarity between Lollard ideas and those of later groups such as the Baptists, Puritans, and Quakers suggests some continuation.