Francesco Melzi and Adoption
Melzi was an Italian aristocrat and was, with Giacomo Caprotti, and possibly also Andrea Boltraffo and Cesare de Sesto, one of Leonardo da Vinci's adopted sons and students. Melzi joined Leonardo's studio in 1513 and was probably the closest to Leonardo, and he was his principal heir when he died in 1519. Their relationship was initially probably more akin to that of master and apprentice, and developed into a personal relationship, quite possibly with a sexual element, as well as, apparently, a legal one. A Spanish source (see below) states: "It is known that he sought to surround himself with young and handsome disciples ... [and] adopted them as his own offspring."
Pall Mall Encyclopaedia of Art. (London: Pall Mall Press, 1971) The Knitting Circle. "Leonardo da Vinci." Available at: www.sbu.ac.uk/~stafflag/leonardodavinci.html "Gays en la Historia." Available at: www.geocities.com/WestHollywood/Heights/5446/historia.htm