THE new republican Government sorely needed iron, and Oliver Cromwell ordered his trusted Sergeant Buck to devise a smelting process fired by coke rather than charcoal.

But Parliament soon discovered that industrial progress depends on individual genius, not on Government policy.

Cromwell’s men sought Dud out in Bristol, but he resolutely refused to give up his secret process to those who had assassinated his King.

He managed to hold out until the Restoration in 1660, but if he expected his old employer’s son, Charles II, to remember his father’s friends, he was disappointed.

Dud’s iron-smelting licence was not renewed, despite repeated applications to the King. Lucrative patents were however granted to others, such as one Colonel Prodger.

But the Colonel Prodgers had as little success as the Sergeant Bucks, and it would be several years before Dud’s process was matched, and bettered, by Abraham Darby - the great-grandson of his sister Jane.