Prior to direct intervention in World War I, Italy occupied the Albanian port of Vlorë in December 1914. In the fall of 1916, Italy started to occupy southern Albania. In 1916, Italian forces recruited Albanian irregulars to serve alongside them. Italy, with permission of the Allied command, occupied Northern Epirus on 23 August 1916, forcing the neutralist Greek Army to withdraw its occupation forces from there. In June 1917, Italy proclaimed central and southern Albania as a protectorate of Italy while Northern Albania was allocated to the states of Serbia and Montenegro. By 31 October 1918, French and Italian forces expelled the Austro-Hungarian Army from Albania. However, in 1920, an Albanian rebellion led the Italians to agree to return the occupied regions to Albania, with the exception of Sazan Island.