in the XIII century the fortress Sarteano was a feud of the Counts Manenti and ceded by the latter to the municipality of Sarteano. In the sixteenth century the medieval fortress, now decrepit, was modified in a more modern military structure according to the construction techniques implemented in Tuscany by the architect Baldassarre Peruzzi. Thus Sarteano had its "citadel" able to resist the attacks of new weapons (Bombarde and archibugi) carried in Tuscany in 1454 by the army of King Afonso of Naples. The male part of the fortress was amended and rendered capable of stably accommodate a garrison of soldiers armed with guns; subterranean passages traversed by soldiers were connected with the access doors of the inhabited area. Since 1590 the Grand Dukes of Tuscany gave the property of the fortress to the Captain Eustace Fanelli and his heirs.