Not really the answer you're looking for, but "translated" is not the term to use here. The English translation of the Greek name Alexandros is "defender of men." The English form of the name is "Alexander."

The last Russian tsar was called "Nicholas" in English by his contemporaries, while the last German kaiser was called both "William" and "Wilhelm." So I would identify that period as roughly the one where the transition took place. Perhaps improved communications between various parts of the world had something to do with it.