The devotio thing is pretty interesting- never heard of that before. What intrigues me about it is that it reminds me of a source I recently read (Leo the Deacon) about a Medieval Roman army (i.e. Byzantine) which was fighting off the Rus (Early Russians/Vikings) One of the emperor's bodyguards saw the Russian leader and charged alone straight into the Russian "phalanx." Not surprisingly he was killed (though he took a bunch of guys out with him), but it inspired the Romans who went on to win the battle. I wonder if this was a survival of sorts of that tradition (or maybe its just a case of a soldier who was slightly nuts).