The following first appeared in Martin Kemp's This and That and is reproduced in Manner of Man Magazine with full written authorisation. All rights reserved.
The next possible mention is the travel diaries of Antonio de Beatis, who visited Leonardo's French residence in the service of the Cardinal of Aragon. Antonio noted three pictures, one of which was of “a certain Florentine woman portrayed from life at the instance [instanza] of the late Magnificent Giuilano de’ Medici”. This might be the Mona Lisa , though Antonio’s precision as a source is questionable. He says that Leonardo suffered paralysis in his right hand and that we “cannot expect more good things from him”. Leonardo was left-handed. If the portrait is the Mona Lisa, it is possible that Giuliano, whom Leonardo served in Rome 1513-16, expressed interested in obtaining the portrait.