In ancient Greece, the chief city of Boeotia, destroyed by Alexander the Great in 336 BC (6)
I believe the answer is:
thebes
(Other definitions for thebes that I've seen before include "Greek city of Oedipus" , "Classical city" , "Ancient city, a rival to Athens" , "Ancient Egyptian or Greek city" , "Ancient Egyptian city sited at modern-day Luxor" .)