Sort of 20 questions played aganst a Genie (no registration required.)
It got my 'Alexander the Great' in about 6 turns 
Just a bit of fun if you are bored. No puzzles tomorrow because of the Posh Party 
It got most of the characters I thought of, although it didn't find King Verence II of Lancre (Discworld). Odd as the name was in its database.
It got Herodotus after 20 questions.
And Pericles.
But not Cleomenes, King of Sparta
But it got Marie Antoinette quite easily.