Just to get back to the point. In the 1800's there was one of the most bloody battles involving strike breaking miners and those on strike in the villages of Seaton Delaval and Seghill. The mine owners had imported Cornish tin miners to do the work of the strikers.
The Cornish miners were known for wearing black mole skin trousers, this apparently giving rise to the phrase 'Blacklegs'. Police and the army were involved and the riots were really bad.

Dave from Seghill