The "Postes Serbes" on these French stamps is not really an overprint, but a handstamp cancel. In 1912 the league declared war on and defeated Turkey, but the allies could not agree on division of the spoils. Dissatisfied with its failure to secure a major portion of Macedonia in the first of the Balkan Wars, Serbia in 1913 turned against and defeated its former Bulgarian ally in the Second Balkan War. Serbia's victory made it the foremost Slavic power in the Balkans but greatly increased tensions with Austria-Hungary. When a Serbian nationalist (acting without governmental collusion) assassinated Austrian archduke Francis Ferdinand in 1914, the empire declared war on Serbia, thus precipitating World War I. The Serbian army fought bravely; but in 1915, when Bulgaria joined the Central Powers and Germany reinforced the Austrians, Serbia was overrun. The Serbian troops and government were evacuated to Kérkira (Corfu), where in 1917 Serbian, Croatian, Slovenian, and Montenegrin representatives proclaimed the union of South Slavs. Stamps of France, 1900-07, with this handstamped control were issued in 1916-1918 by the Serbian Postal Bureau, in the Island of Corfu, during a temporary shortage of Serbian stamps. One the one cent to 35 cent stamps, the handstamp covers 2 or 3 stamps. It was applied after the stamps were on the cover, and often (but not always), no further cancellation was used.