Complex sentence: Another war erupted, this time over a boundary dispute between Thebes and Athens; once again, Thebes was defeated after King Pandion II of Athens received aid from the Thracian king Tereus.
Split into simpler sentences: Another war erupted, this time over a boundary dispute beteween Thebes and Athens. Once again, Thebes was defeated after King Pandion II of Athens received aid from the Thracian king Tereus.