Sir Thomas established his works beyond Bellemondegate, where now mountains of refuse shale are piled up. For some time the works yielded but small profit, and it was not until Chaloner got more workmen from Rochelle that they became a success, after which they yielded a handsome revenue, and had the effect of breaking down the Italian monopoly, and reducing the price of alum in England to one-half its former cost. When Chaloner had got the mines and works into thorough working order, King Charles I., at the instigation of some of his rapacious courtiers, made a claim to them as Crown property, and he was compelled to surrender them. They were then let to Sir Paul Pindar, at a rent of £12,500 per annum, to be paid into the Royal Exchequer, besides £1,600 per annum to the Earl of Mulgrave and £600 per annum to Sir William Pennyman, but they were restored to the Chaloners by the Long Parliament. Eight hundred men were employed on the works, and the alum sold at £26 per ton, which left a large residue of profit. Other mines were discovered in Cleveland, on the estates of the families of Phipps, Pennyman, Fairfax, D'Arcy, and Cholmley, when competition brought down the price, and consequently reduced the profits; and, as some of these were situated nearer the sea-coast, with greater facilities for shipment, the Guisborough mines became less and less profitable, and were eventually abandoned. This conduct on the part of King Charles caused the Chaloners to become zealous Parliamentarians in the Civil War. Sir Thomas's sons, James and Thomas, drew their swords against the King, and both sat as members of the High Court of Justice for his trial. The former was tried as a regicide after the Restoration, was condemned to death, and drawn on a hurdle to Tyburn for execution, but received a reprieve when the halter was round his neck; was remitted to the Tower, and died of poison, it was reported, by his own hand, "an invention," says Markham, in his Life of Fairfax, "of the carrion vultures of the Restoration." The latter, at the Restoration, was included in the list of those excluded from pardon, but saved his life by flight. Winstanley says of him, "He had travelled far in the world, and returned home poysoned with that Jesuitical doctrine of King-killing, which he put in practice, being the great speech-maker against the King, ... and a great stickler for their new Utopian Commonwealth, but upon His Majestie's return fled, his actions being so bad as would not endure the touchstone." The Maiden of Marblehead.