Kefalonia or Cephalonia, formerly also known as Kefallinia or Kephallenia (Κεφαλληνία), is the largest of the Ionian Islands in western Greece and the sixth-largest island in Greece after Crete, Euboea, Lesbos, Rhodes and Chios. It is also a separate regional unit of the Ionian Islands region. It was a former Latin Catholic diocese Kefalonia–Zakynthos (Cefalonia–Zante) and short-lived titular see as just Kefalonia. The largest cities of Cephalonia are Argostoli and Lixouri.