Strike action, also called labor strike, labour strike, on strike, greve (of French: grève), or simply strike, is a work stoppage caused by the mass refusal of employees to work. A strike usually takes place in response to employee grievances. Strikes became common during the Industrial Revolution, when mass labour became important in factories and mines. In most countries, strike actions were quickly made illegal, as factory owners had far more power than workers. Most western countries partially legalized striking in the late 19th or early 20th centuries.