Cetona is known until from the 1073 when it belonged to the County of the Aldobrandeschi of Sovana.
Then was under Orvieto and Perugia.
And in the 1418 Cetona was conquered from Sienese Republic and from the 1555 Cetona was attached to the Granducato of Tuscany.
A counsel: visit the Civic Museum of the Prehistory of Mount Cetona (entrance fee).
Chiusi and King Porsenna (html file)
Archaeological park of Belverde (html file)