Local historians and authors have investigated the millennia-long history of the Ossola Valley, writing, with great skill and passion, countless texts and books that today constitute an important collection of information related to real events that took place in this area of Piedmont on the border with Switzerland.
The Ossola Valley appears to have been inhabited well before the Lepontii mentioned by Ptolemy: this is evidenced by numerous archaeological finds discovered in the necropoleis of Ornavasso and Migiandone, which date back to a pre-Roman civilization.
These finds are now collected in the archaeological museums of Varzo and Mergozzo: they tell the story of how the Ossola Valley was invaded by the Gauls, of clashes between the Cimbri and the Romans and of the barbarians that ruled the land; they recount events, battles and occupations that culminated, at the end of the 5th century, with the arrival of the Lombards.
In 1014, the Ossola Valley was bestowed to the Bishop of Novara. It later became part of the Swiss confederation, before returning to the Duchy of Milan at the start of the 16th century.
The current Formazza Valley, Ornavasso in Lower Ossola and Macugnaga in the Anzasca Valley were colonized around 1300 by the Germanic people from the Valais area, who brought with them Walser traditions that are still alive and tangible in these border areas.
The rule of the Visconti (a historic epoch attested to by the splendid Castello Visconteo in Vogogna) preceded that of the Sforza and Spanish domination, leading to one of the most tragic periods in the Ossola, which witnessed civil strife, famine and devastating epidemics.