Charles Nicholl has immersed himself in manuscripts, paintings and artefacts to produce an intimate portrait of Leonardo He uses these contemporary materials - his notebooks and sketchbooks, eye witnesses and early biographies, etc - as a way into the mental tone and physical texture of his life and has made many discoveries about him, his work and his circle of associates The book identifies what Nicholl argues is an unknown portrait of the artist hanging in a church near Lodi in northern Italy It also contains new material on his eccentric assistant Tomasso Masini, his homosexual affairs in Florence, and his curious relationship with a female model andor prostitute from Cremona