I didn't actually mean it was the common modern name for the town. I meant it was still the common name for the battle, which is what we're discussing. Although I can see that might have been unclear. But it's not an inaccurate or incorrect name for the town either (although I wouldn't use it personally); not the same thing as not being the common name. To use an analogy, in British English we don't usually use Marseilles any more either, but that doesn't mean that Marseilles is incorrect and Americans generally still use it. I'm generally all in favour of using the local names for towns (except for obvious exceptions like Venice, Florence, Munich, etc, where to use the native name would be seen as unnecessarily pretentious in English), but not for historical events which have gone down in English under another name.