Located in a morphologically extended valley fifteen kilometers from the shores of Lake Olginate to Ambivere and officially named Val San Martino starting from the first half of the fifteenth century, Calolziocorte has its roots in a very distant past.
Indications of a probable human presence in prehistoric times are the remains of some pile-dwelling structures found at the Lavello, evidence, perhaps, of a first settlement located along the banks of the river Adda. Even in the protohistoric era, in all likelihood, the territory of Calolzio was the subject of some population: leaving aside the various hypotheses about the pre-Roman origin of the locality, the presence of a settlement referable to the Iron Age and to the Celtic culture of Golasecca is significant ( IX-V century BC) identified at the nearby Rocca of Somasca.
The vestiges of the Roman presence dating back to the imperial era are evident. Crossed by the piedmont road that connected Brescia, Bergamo, Como and which crossed the river Adda thanks to the bridge of Olginate, referable to the III century AD, the settlement of Calolzio gained importance finding in this road the reason for its development.
In addition to the numerous sarcophagi with a sloping lid and a small necropolis found in La Gerra, particular attention should be paid to finding the sacred marble inscription with a dedication to Diana, goddess of hunting, woods and the moon, found near the parish church of Lorentino datable between the I and the II century.
The first written record of a place of Calolzio, or Court, dates back to 774, when Rado de Curte appears as a witness in a Bergamo parchment. The character would be the oldest inhabitant of Calolziocorte whose documented proof exists.
It is very probable that already in the early Middle Ages there existed in Calolzio, and always in the locality of La Gerra, a primitive church dedicated to San Martino Bishop of Tours so as to then extend the same dedication to the entire valley on it gravitating.
In 1274 Napoleone della Torre conquered the San Martino Valley and its chief town: in those years, on Calolzio, strong was the power exercised by the noble feudal family of the Benaglio, among other holders of numerous castles and ally of the Torriani in an anti-Visconti key. Among the numerous military and political events that followed this tragic period of infighting, we recall the battle of Campo Cerese (1398) between the Guelphs of Calolzio and the Ghibellines of Olginate.
With the treaty stipulated in April 1454, Val San Martino passed definitively under the dominion of the Republic of Venice, which for some decades had begun to appear in the Calolian territory in order to occupy Lecco. With the gentle rule of the Serenissima, Calolzio inaugurated a period of greater tranquility and prosperity and drew many benefits from the various privileges that the Venetian Government granted it as a borderland with the Duchy of Milan. The strategic position and the presence of important railway crossroads favored the development in Calolziocorte of numerous industrial settlements, especially in the 20s of the last century. To remember the establishment “Sali di Bario”, from all the Calolziesi known as “Fabricù”. In the craft sector the artisan production of agricultural tools and metal processing are very widespread and renowned.