sentence1: It is possible, though no such attack took place, writes historian John Julius Norwich in his forthcoming book Shakespeare's  The Great Plays and the History of England in the Middle  1137-1485 . Norwich, who calls the command the darkest stain on [the historical Henry's] reputation, says that so many of Henry's men refused to obey his order that he was at last obligated to designate 200 of his own archers specifically for the task.
sentence2: Norwich says Henry's men wouldn't obey when he told them to attack.