Landowners with substantial estates could make a fortune from leasing out mineral rights – much more than they would have made through agriculture. They quickly became hugely wealthy, earning them the name ‘mineral lords’.
Cornish mining made substantial technological, social and economic contributions to the British industrial revolution and introduced pioneering industrial practices overseas. This occurred at a crucial formative period in the development of modern industrial society and played a key role in the growth of a global capitalist economy.
Gwennap was once described as the "richest square mile in the Old World".
The mineral lords had a key part to play. Not only did they help finance the mines, but they were also influential in helping to set up industrial infrastructure, ancillary businesses and settlements.
Who were the mineral lords?
The Williams family of Scorrier, the Basset family, Sir William Lemon of Carclew and Lord and Lady de Dunstanville were among the most successful mineral lords in Cornwall. Many of them possessed huge acreages of mineral-rich land and were also able to invest capital into the mines themselves.
Much of the wealth they amassed was transformed into great mansions, estates and extensive gardens, many of which can still be seen today. Older estates went through elaborate transformations, complete with lavish ornamental gardens.
Development and influence over the mines
Mineral lords had a huge amount of influence over the development of the mines. John Williams promoted a major drainage adit driving scheme which became arguably the most dramatic engineering achievement within the district. Begun in 1748 to drain Poldice Mine, this extraordinary drainage system was gradually extended to the other mines of the district and eventually became known as the Great County Adit.
Setting up a new mine was a costly business. Adventurers would help finance the cost in return for a share in the profit. There were huge fortunes to be made, but it was a risky business. The larger their share, the larger their profit – or loss. If the mine failed to produce the anticipated amount of ore or ran into problems, they could find themselves in financial difficulty when a ‘call’ for funds was made.
Mineral lords who had the financial capital to also invest in mines stood to gain the most. Sir William Lemon held a quarter share in one of the most profitable of Cornish mines, Wheal Unity.