 It has long been the best-known source of information on the provenance of the work and identity of the sitter.Leonardo's assistant Salaì, at his death in 1524, owned a portrait which in his personal papers was named "la Gioconda", a painting bequeathed to him by Leonardo.That Leonardo painted such a work, and its date, were confirmed in 2005 when a scholar at Heidelberg University discovered a marginal note in a 1477 printing of a volume by ancient Roman philosopher Cicero.