Which artist painted the "David with the Head of Goliath"?

I love Caravaggio!

When I don't know the answer I go for the one that seems to be the most well-known, and this time I was right.

Saw the Caravaggio Head of John the Baptist at the National Gallery, London a couple of weeks ago.

Again this annoys me, it mentions blood dripping from the head and the sword, its of which we can't see. it doesn't even give his full name or any kind of biography. I would have appreciated some info.