The Treaty of London, also known as the London Pact (Patto di Londra, in Italian), was negotiated secretly by three major Allied Powers (France, Russia, Great Britain) and Italy. Since the Italian territorial demands included the Yugo-Slavic lands under Austria-Hungary, the negotiations had to involve also the future borders of two cobelligerant Allied states, the kingdoms of Serbia and Montenegro.
However, the territorial promises to the latter were fairly precise only along the areas assigned to Italy. Thus, the Kingdom of Serbia was promised Split (Spalato, in Italian), the coast and islands south of Krka to Dubrovnik (Ragusa), and peninsula Peljesac (Sabbioncello). The Kingdom of Montenegro was assigned Dubrovnik, and the coast south to the Albanian port San Giovanni di Medua. Also, but less precisely, Serbia was promised Bosnia-Herzegovina, Srem, Backa, Slavonia (this one against the Italian objections), and some unspecified areas of Albania (to be divided between Serbia, Montenegro, and Greece). The Italians insisted, and the Allies agreed, that the question of the Croatian coast between Zadar (Zara) and Istra (Istria) should be settled after the war. They also insisted that Serbia should not be informed about the agreements. This, however, the Allies overruled by sending to the Government of Serbia an official Note, dated August 4, 1915, confirming the postwar territorial claims of Serbia and Montenegro.
At the Paris Peace Conference, the Italians insisted that they will negotiate only with their wartime allies Serbia and Montenegro, not with defeated enemies included in delegation of the new state of Serbs, Croats and Slovenes. In particular they were incensed that three members of the delegation were former Austro-Hungarian deputies (Croats Ante Trumbic, Josip Smodlaka, and the Slovene Otokar Ribarz), and that one (the Slovene Ivan Zolger) had served as Minister in the wartime Austrian Cabinet. But the Italians finally gave in, primarily under the pressure of the then US President Woodrow Wilson.
Rene Albrecht-Carrie, ITALY AT THE PARIS PEACE CONFERENCE. 1966
Ivo J. Lederer, YUGOSLAVIA AT THE PARIS PEACE CONFERENCE. 1963