After defeating the feudal lords of the Versilia
region, who controlled their land from castles perched on the neighbouring hills, Lucca fought against Pisa for the control of the coast in the XIIth
The lords of Montemagno became Lucca's allies and helped to build another castle
that was supposed to contrast both the Pisans and the troops of the lords of Vallecchia and Corvaia, relentless enemies of the government. The feudal regime definitively collapsed in Versilia around the middle of the XIIIth
century and from then on the castle of Montemagno probably fell into neglect. An interesting piece of information comes from a document dated 1411 and kept in Lucca's Public Record Office. In this contract a certain 'Mucius' of Naples rents from the Commune of Lucca " una pezza di terra vineata et selvata et boschiva cum Castro distructo et cum Edificius Palatium murati et Ecclesia sopra se in loco detto al Castello di Montemagno": so we learn that the 'castro', i.e. the castle, was indeed already destroyed.