Leonardo di ser Piero da Vinci (1452-1519) was an immensely multi-talented Italian Renaissance polymath: architect, anatomist, sculptor, engineer, inventor, geometer, musician and painter. He has been described as the archetype of the "Renaissance man" and as a universal genius, a man infinitely curious and infinitely inventive. He is widely considered to be one of the greatest painters of all time.
Besides the work for which he has become famous, Leonardo was hired (perhaps by force) around the year 1505 by a new patron he knew as "Captain Tancredi" - in reality, Scaroth of the Jagaroth. Tancredi asked him to paint six extra copies of his most famous work, the Mona Lisa. The plan was apparently foiled by the arrival of the Fourth Doctor from the year 1979, who was seeking clues to the plot of Count Scarlioni (another of Scaroth's time-splintered selves) to steal the Mona Lisa in that year. After being briefly captured and interrogated by Tancredi, the Doctor manages to escape back to 1979, after writing "This is a fake" on Leonardo's canvasses in felt tip (City of Death). Although the Doctor did not meet Leonardo in person in that period, he did leave him a note which suggested a degree of familiarity already existed, and that perhaps the two had previously met, or would meet in the future.
The Monk's diary recorded a meeting with Leonardo where the renegade claimed to have provided the inspiration for at least some of the apparently-anachronistic inventions the genius later designed. (DW: The Time Meddler)
