Coal miners have been hard at work for centuries, but they became increasingly important in the Industrial revolution when coal was used to fuel stationary and locomotive engines and heat buildings. Owing to coals strategic role as a primary fuel, coal miners have figured strongly in political movements. From the late 19th century down to the through to the early twenty first century coal miners in many countries have been a frequent presence in industrial disputes with the management of coal mining enterprises. Coal miners politics whilst complex have frequently been radical with a strong leaning towards far-left political views. A number of radical far-left political movements have had the support of both coal miners themselves and their trade unions.