Basil Valentine is the Anglicised version of the name Basilius Valentinus, ostensibly a 15th-century alchemist, possibly Canon of the Benedictine Priory of Saint Peter in Erfurt, Germany but more likely a pseudonym used by one or several 16th-century German authors.
According to John Maxson Stillman, who wrote on the history of chemistry, there is no evidence of such a name on the rolls in Germany or Rome and no mention of this name before 1600.
During the 18th century it was suggested that the author of the works attributed to Basil Valentine was Johann Thölde, a salt manufacturer in Germany who lived roughly 1565–1624.
These were accompanied by woodcut engravings from later publications in the early seventeenth century.
Numerous publications on alchemy in Latin and German were published under the name Basil Valentine.