Located on the hills between Bagnone and Villafranca, the village of Castiglione del Terziere has medieval origins and was originally known as Borgo dei Corbellari. In the 13th century, it became known as Castiglione del Terziere, as it represented a third (terziere) of the feudal estates left by Obizzino Malaspina to his heirs. In 1451, it came under the control of the Republic of Florence, becoming the political center of reference and the seat of the Captaincy of Justice in the region.
The village is dominated by the Castle of Castiglione del Terziere, which dates back to the 6th–7th centuries. It was renovated in 1351 by Franceschino Malaspina and, in more recent times, by philanthropist Loris Jacopo Bononi. During the rule of Castruccio Castracani, lord of Lucca, the castle reached the height of its importance, becoming a strategic stronghold in his attempt to unify Lunigiana, Garfagnana, Versilia, and Lucchesia into a single state.
Other notable monuments include the original church built in the 16th century, which was abandoned in 1783 and replaced by the new Church of San Leonardo in 1787. Also located in the village is the former Convent of the Santissima Annunziata, built between 1501 and 1508, later entrusted to the Servite Fathers and now restored.
