The name comes from the latin name Bonus COnventus ( = happy, lucky community).
That name is an index of good gathering of people who settled there after being attracted by fertility of earth and by the chances they could get by the proximity of the two rivers Arbia and Ombrone, but above all by the real closeness to the ford of the river along a main way, the Francigena way.
There the pilgrims used to stop their trip to rest and eat by makig use of the services of the modest local craftmen,
Or by purchasing the products and fruits of that land.
Buonconvento lays 25 km far from Siena, it is located within Arbia valley yet, it seems that its origins date back to the 12th century by placing along the Francigena way as a group of modest lodgements of farmers, of small salesmen and craftsmen.
The first historical document where Bonus Conventus is quoted dates back to the year 1191; In that eve Philip August the King of France, coming back from the third Crusade in Holy Land, by running along the same Francigena way he remembers he had stopped in the manor of Bon-Couvent.
Soon after that place ended under the power of Siena which was provided with earth products by that small centre.
All around there the aristocracy in siena lived in the colony houses and occupied the fertile land having it worked by the peasants of that village under the métayage.
Therefore, as times would go by Buonconvento ended by suffering the consequences of a war between Siena and Firenze people and passed a period of crises and incursions.
Thus the village, at the end of 1300 was provided with a thick townwalls and a fortress that is still standing nowadays.
IN 1385, after Siena had ordered to the inhabitants of the close communes to go and live inside the walls of Buonconvento, a Podestà's palace was built inside the same walls with its civic tower;
thus, in the first years of the 15th century Buonconvento achieved 32 Podestà's properties; among them there was Monterongriffoli, Lucignano d’Arbia, Corsano, Monteroni d’Arbia, Serravalle and Bibbiano.
In 1480 the Governors from Siena gave those people the privilege of being Siena citizens but after several events,
as Siena felt in 1559 Buonconvento passed under the power of the Medicis thus being part of the Granduchy of Toscana,
remaining along with its podestry the main centre of Arbia Valley.
After a long period of quietness Napoleone Bonaparte came with his troups to conquer the village that then was shared
in two parts: the one preserved the actual name and the other went to constitute the Commune of Monteroni d'Arbia.