Grand Allies
The Grand Allies, or Grand Alliance, was a cartel of English coal-owning families formed in 1726. It was based on the Northumberland and Durham Coalfield, and played a major role in the economics of mining coal from the field for about a century. Over time, other families joined the original main three. The Grand Allies were superseeded by the "Limitation of the Vend", another north eastern cartel.