By the 1912 treaty signed in Ouchy, Italian sovereignty was acknowledged by the Ottomans. Italy officially granted autonomy to the region around Tripoli after the war, but gradually occupied the region called "Tripolitania" by the Italians. Originally administered as part of a single colony, Tripoli and its surrounding province were a separate colony from 26 June 1927 to 3 December 1934, when all Italian possessions in North Africa were merged into one colony called "Italian Libya".