<P> The Black Death was a pneumonic plague pandemic, which reached England in June 1348 . It was the first and most severe manifestation of the Second Pandemic, caused by Yersinia pestis bacteria . The term "Black Death" was not used until the late 17th century . </P> <P> Originating in China, it spread west along the trade routes across Europe and arrived on the British Isles from the English province of Gascony . The plague seems to have been spread by flea - infected rats, as well as individuals who had been infected on the continent . Rats were the reservoir hosts of the Y. pestis bacteria and the Oriental rat flea was the primary vector . </P> <P> The first known case in England was a seaman who arrived at Weymouth, Dorset, from Gascony in June 1348 . By autumn, the plague had reached London, and by summer 1349 it covered the entire country, before dying down by December . Low estimates of mortality in the early twentieth century have been revised upwards due to re-examination of data and new information, and a figure of 40--60% of the population is widely accepted . </P> <P> The English government handled the crisis well, and the country did not experience the extreme reactions that were seen elsewhere in Europe . The most immediate consequence was a halt to the campaigns of the Hundred Years' War . In the long term, the decrease in population caused a shortage of labour, with subsequent rise in wages, resisted by the landowners, which caused deep resentment among the lower classes . The Peasants' Revolt of 1381 was largely a result of this resentment, and even though the rebellion was suppressed, in the long term serfdom was ended in England . The Black Death also affected artistic and cultural efforts, and may have helped advance the use of the vernacular . </P>

What fraction of the british population was killed by the black death