<P> Stone and Bronze Age flint axes have been discovered embedded in coal, showing that it was mined in Britain before the Roman invasion . Early miners first extracted coal already exposed on the surface and then followed the seams underground . </P> <P> It is probable that the Romans used outcropping coal when working iron or burning lime for building purposes . Evidence to support these theories comes mostly from ash discovered at excavations of Roman sites . </P> <P> There is no mention of coal mining in the Domesday Book of 1086 although lead and iron mines are recorded . In the 13th century there are records of coal digging in Durham and Northumberland, Nottinghamshire and Derbyshire, Staffordshire, Lancashire, the Forest of Dean and North and South Wales . At this time coal was referred to as sea cole, a reference to coal washed ashore on the north east coast of England from either the cliffs or undersea outcrops . As the supply of coal on the surface became used up, settlers followed the seam inland by digging up the shore . Generally the seam continued underground, encouraging the settlers to dig to find coal, the precursor to modern operations . </P> <P> The early mines would have been drift mines or adits where coal seams outcropped or by shallow bell pits where coal was close to the surface . Shafts lined with tree trunks and branches have been found in Lancashire in workings dating from early 17th century and by 1750 brick lined shafts to 150 foot depth were common . </P>

When was coal first mined in the uk