A question from Yahoo! Answers:
Alexander The Great…what was his family name?
Back in those days, there were no family names. People were known by the lands they owned (or, failing that, by their birthplace or place of residence, which for most people was the same place anyway; for example, Herodotus, “the father of history,” was known as Herodotus of Halicarnassus in his lifetime) or by nicknames they earned by doing something of note.
Alexander’s family was the royal house of Macedon, so his father was known as Philip II of Macedon; Alexander was crowned Alexander III of Macedon, but eventually, due to his success as a military leader, he became known as Alexander the Great (“Megas Alexandros” in Greek).