Dictionary of National Biography, 1885-1900/Ashton, Thomas de (fl.1446)
ASHTON or ASSHETON, Sir THOMAS de (fl. 1446), alchemist, born in 1403, was the son and heir of Sir John de Ashton, of Ashton-under-Lyne [see Ashton, Sir John de], who died in 1428. Permission was granted by Henry VI to Sir Thomas to transmute the precious metals, and on 7 April 1446 a special order was issued (Rot. Pat. 2, No. 14), encouraging two Lancashire knights, Ashton and Sir Edmund de Trafford, to pursue their experiments in alchemy, and forbidding any subject of the king to molest them. Sir Thomas married Elizabeth, daughter of Sir John Byron, by whom he had eleven children. The eldest son, John, was knighted before the battle of Northampton, 10 July 1460, and died in 1508.
[Fuller's Worthies (ed. Nicholls), i. 555; Biographia Britannica; Foster's Lancashire Pedigrees; Baines's History of Lancashire (ed. Harland), i. 133.]