The archeological excavations made by the Universities of Pavia and of London during the latest years, brought to light inscriptions, cemeteries of the Imperial period, as well as ruins of fortifications and an entrance door in the boundary wall.

This was the place where Queen Theodolinda, widow of Authari, married Agilulf, Duke of Turin, in 590.

Queen Gundeberga, daughter of Theodolinda and wife of Arioald, after being charged with the betrayal of her husband, was imprisoned in a tower in 629 and released after three years, thanks to the first "Judgement of God" ever celebrated in Italy.

In the Carolingian period, it was the place of a comitatus and in 1024 the fortress of Lomello was elected to the residence of the Palatine Counts while, in the same years, the basilica of Santa Maria Maggiore was built as a mark of wealth and power.

Francesco Sforza assigned the County of Lomello to the Crivelli family, who held it continuously until 1760.