The feudal system in medieval England compelled peasants to spend a certain amount of time working for free for large landowners. Many were also barred from leaving their area without permission and had to pay to get married. This semi-slavery, or serfdom, gave the landed gentry vast power.
Things began to change after the Black Death cut the population in half in 1348, according to estimates. The resulting labour shortage gave surviving peasants power to demand better wages.
But as the peasantry gradually became better off, Parliament tried to shore up serfdom using laws fixing wages, and increasing punishments for serfs who ran away. Meanwhile, it also drove through a series of taxes to cover the cost of wars with France.
The most unpopular was the poll tax of the 1370s, levied at a flat rate on everyone over 15 (so peasants paid a higher proportion of their income than the wealthy). Tensions exploded in 1381 when an official tried to collect taxes from villages near Brentwood in Essex.
The subsequent revolt swept the countryside. By June, led by Jack Straw and Wat Tyler, the peasants had entered the City of London and forced King Richard II to agree to their demands, including the abolition of serfdom and the end of the poll tax. The king reneged on his promises after Tyler was killed and the revolt crushed.
However, most historians agree that the revolt accelerated the decline of serfdom, although the last serfs were not freed until as late as 1571. And no government attempted to levy a pure poll tax again until the ill-fated Community Charge of the late 1980s.