Gian Giacomo Caprotti and Adoption
Also known as Salai and Andrea Salaino
Caprotti was a student of the immortal Leonardo da Vinci, who was his frequent model and collaborated with him in some of his paintings. But he was probably more than this. Two sources (Krämer and Schmidt, and "Romantic Notions") state that he was Leonardo's adopted son, probably dating from 1490 when he went to him as an apprentice. More generally accepted is the assumption that they became lovers. Leonardo gave the young Caprotti the name Salaì (Little Devil, or Devil's Offspring), because of his almost intolerable behavior: continually lying, stealing and breaking things. In spite of this they were together until Leonardo's death in 1519, and Salaì inherited the master's vineyard at Milan.
Another protégé, the aristocrat Francesco Melzi, is also believed to have been adopted by Leonardo.
Krämer, Walter, and Schmidt, Michael. Lexikon der Populären Listen: Gott und die Welt in Daten, Fakten und Zahlen. Aktualisierte Ausgabe. (Zürich: Piper München, 1999), p. 17 Hackett, Regina, "Inspiration springs eternal from the master's artistic well." Available at:  "Heroes, Myths, & Legends: Gay and Lesbian People in History: Leonardo da Vinci, 1452-1519." Available at:  Provenzano, Jim. "Romantic Notions: Leonardo da Vinci and Salai." Available at:  Wealthy, Famous, Noble or Divine Adoptive or Foster Families]]