Overview
Medusa is either of two paintings described in Giorgio Vasari's Life of Leonardo da Vinci as being among Leonardo's earliest works. Neither painting survived.
First version
In his Vita di Leonardo (1568), Vasari reports that, as a very young man, Leonardo represented the head of Medusa on a wooden shield after a request by his father, Ser Piero da Vinci:
Although art historians have doubted the veracity of this anecdote, Leonardo's shield (long since lost) has been said to inspire several early 17th-century painters who may have seen it in the collection of Ferdinand I de Medici. Rubens and Caravaggio are known to have painted their own versions of the subject, but their indebtedness to Leonardo's painting (assuming they had seen it) is uncertain and potentially unknowable.
From Wikipedia (CC BY-SA 4.0).