The river Judrio (Idrija in Slovenian), located downstream of Colle San Giorgio has represented for centuries a natural border, first between the county of Gorizia and the Kingdom of Lombardy-Venetia, then between the Habsburg Empire and the Kingdom of Italy. During the Habsburg domination, the production of white wines in the area was monopolised by the nobles and mainly destined for the Carinthian market.
The Collio physically and politically was a unique area that after the end of the Second World War was divided between Italy and Yugoslavia, with the peace treaty of Paris. Currently the largest part of the area, called Brda, belongs to the Republic of Slovenia. A unifying element between the two areas, in addition to the common vocation for viticulture, is the cultural footprint of Central European origin