What European country was last to be unified into a single state?

Germany was the last major European country to be unified into a single state, achieving this in 1871. The unification was largely driven by Otto Von Bismarck and culminated in the proclamation of the German Empire at the Palace of Versailles after the Franco-Prussian War. Prior to this, the region was a collection of independent states and principalities. Italy also experienced unification around the same time, but Germany was the last significant unification in Europe.