Sir Thomas de Ashton or Assheton (fl. 1446), was an English alchemist.
Ashton was born in 1403, the son and heir of Sir John de Ashton, of Ashton-under-Lyne, who died in 1428. His half-brother Ralph de Ashton seems to have inherited the main family home, Ashton Hall. From roughly this date, differences appear in the coat of arms, motto and spelling of the two families, indicating that Sir Thomas may have distanced himself from his unpopular half-brother.
Permission was granted by Henry VI to Sir Thomas to transmute the precious metals, and on 7 April 1446 a special order was issued, 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, born in Kingsley, Lancashire, England, 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, was MP for Lancashire in 1472 and died in 1508.
Douce Ashton, birth date 1435; married Thomas (Sir) Gerard Knight, born 15 Jul. 1431 in Kingsley, Lancs, England, died 27 Mar. 1490 in Kingsley, Lancs., England
Thomas de Ashton (alchemist) is not, Sir Thomas de Ashton Lord of Croston d. 17 Oct 1407 and, is not the medieval Thomas de Aston, a 13th-century monk d. 7 June 1401: these two men are in Lincoln Cathedral.
Heritage Consulting. Millennium File [database on-line]. Provo, UT, USA: Ancestry.com Operations Inc, 2003. Original data: Heritage Consulting. The Millennium File. Salt Lake City, UT, USA: Heritage Consulting.
"". Dictionary of National Biography. London: Smith, Elder & Co. 1885–1900.