From Wikipedia: A portrait, supposedly of Christopher Marlowe. There is in fact no evidence that the anonymous sitter is Marlowe, but the clues do point in that direction. Marlowe was 21 years old in 1585, when the painting was made. He was also the only 21-year old student at Corpus Christi, where the painting was later found.
New scholarship from the Oxford University Press suggests that Shakespeare had help from Christopher Marlowe when writing Henry VI, parts 1, 2 and 3. Corpus analysis helps solve the puzzle! More.