It is located in the historical region of Garfagnana, at the confluence of the Serchio and the Turrite Secca rivers, close to the intersection of roads passing through the Apennine Mountains and the Apuan Alps.

From the 13th century Castelnuovo di Garfagnana developed as a market town due to its position close to rivers which were important trading routes.

In 1316, control of Castelnuovo di Garfagnana was given to Castruccio Castracani, who built a bridge in order to join the castle to the village.

At the beginning of the 15th century the inhabitants of Castelnuovo di Garfagnana rebelled against the domination of Lucca, putting themselves under the protection of the Estensi family of Ferrara in 1430.

In the following years the House of Este returned to power; their domination lasting up to the invasion of the territory by the French army led by Napoleon Bonaparte.