Possible Clues:

• Cross individual returned ring briefly for old historian
• What's noble about extremely acidic Greek commander?
• Greek historian's cross, English number to call cut short
• Greek general and historian who was a disciple of Socrates
• Greek writer (Anabasis)
• Greek historian
• Greek historian (Anabasis)
• Greek historian's element? Work hard in it
• Greek general, a disciple of Socrates
• Ancient Greek general