What did all the Greek city stars have in common

they simply believed in themselves. they spoke the same language, they had a common culture, they shared a love of beauty and competition. and they were located on the same peninsula.

There you go

Explanation:

What did all the Greek city states have in common

Their city-states were located on the same peninsula.

They were not forced to believe - -> they simply believed in them.

They had a common culture - their love of beauty and competition to name two. They spoke the same language.