evidence: A turning point in the fortunes of Montenegro came when Serbia declared war on the Ottoman Empire in 1876. (See Serbo-Turkish War.) Montenegro, under Prince Nikola Petrović (Nicholas I), joined Serbia immediately and Russia the following year. Although the territorial gains awarded to Montenegro by the initial Treaty of San Stefano were reduced at the Congress of Berlin in 1878, the state virtually doubled in area, and for the first time its borders were set down, however vaguely, in an international treaty. Most significantly, Montenegro secured vital access to the sea at Antivari (modern Bar) and Dulcigno (Ulcinj). Although the hostility of the other great powers to a Russian naval presence in the Mediterranean tended to restrict the use of these ports, Montenegro was now far more open to communication with the developing industrial economies of western Europe. Trade expanded, tobacco and vines were cultivated, a state bank was founded, motor roads were built, a postal service was initiated, and in 1908 the first railway (from Antivari to Virpazar on Lake Scutari) was opened. The majority of the investment was by foreign (especially Italian) interests.