From this he recognised that the rock from which the alum was made was similar to that abundant in several areas in and around his cousin's Guisborough estate, in present-day Redcar and Cleveland. In 1606-07 Sir Thomas (the courtier) went into partnership with Sir David Foulis and with Lord Sheffield and Sir John Bourchier, obtaining a monopoly for 31 years of manufacture in northern England.
He realized that the rock used to make alum was similar to the one found at his cousin's estate in Guisborough, which is now part of Redcar and Cleveland. In 1606-07, Sir Thomas (the courtier) partnered with Sir David Foulis and Lord Sheffield and Sir John Bourchier to obtain a monopoly for 31 years on alum production in northern England.