Why in English did we change Normandie to Normandy?

In English we changed Normandie to Normandy because that's how it sounded to us. Italy instead of Italia, and Spain instead of Espa�a came from medieval times. There were no standard spellings in English until relatively recently. Also, in medieval times, when words were borrowed, they were often inadvertently changed (as in common pronunciation), or intentionally changed (as an Anglicism). We could also be going by what other people call the country, but not the people themselves. For example, Japan got its name from a Chinese word; in Japanese it is called Nippon.