Giorgio Vasari, who was Leonardo's first biographer (a person who writes about the life of another person), thought the painting was of a person named Lisa Gherardini. Speculation over the painting's model was solved in 2008 by Dr Armin Schlechter, a manuscript expert. Notes discovered in Heidelberg University Library which were written by Agostino Vespucci, a Florentine city official, reinforced Vasari's earlier identification of the model. Lisa was the wife of Francesco del Giocondo a rich silk merchant, who lived in Florence.