In my view, only the black plague and class inequality.
The Black Death was a disease of the rat flea that spread and devastated Europe in the fourteenth century, but reached England again in the second outbreak in the sixteenth century.
The world wars happened in the twentieth century, so they are not an answer.
Unemployment and lack of manpower are the opposite of each other, but none have actually reached England. First, because the population of that time was basically rural and lived subsistence. The event of the Industrial Revolution caused a great demand by manpower, that was satisfied by the peasant class, that migrated to the city.
However, class inequality has always been present. This comes from the age of feudalism, but it grew especially during the Industrial Revolution, which produced a capitalist bourgeoisie and a mass that worked in factories for low wages and abusive hours.
