King Henry II had protected the Jews of England because of their economic role in Medieval Europe. When he was succeeded by the Crusader king, Richard I, crusade fervor was sweeping across Europe. This fervor could quickly turn violent and their were violent incidents against Jews and other "outsider" groups scattered in towns across England.
After a particularly frightening disturbance in York, the city's Jewish community took refuge in the wooden keep where they were besieged by a violent mob. Eventually, rather than turn themselves over to the hands of the mob, many of York's Jews committed suicide and set fire to the tower. The survivors, who emerged the next day, were set upon and massacred.
Eventually, the Royal Chancellor dismissed the sheriff and constable and fined the citizens of York for their part in the tragedy.