While Powers were asking Empire to reform Macedonia, under the encouragement of Russia, a series of agreements were concluded: between Serbia and Bulgaria in March 1912, between Greece and Bulgaria in May 1912, and Montenegro subsequently concluded agreements between Serbia and Bulgaria respectively in October 1912. The Serbian-Bulgarian agreement specifically called for the partition of Macedonia which resulted in the First Balkan War. A nationalist uprising broke out in Albania, and on 8 October, the Balkan League, consisting of Serbia, Montenegro, Greece and Bulgaria, mounted a joint attack on the Empire, starting the First Balkan War. The strong march of the Bulgarian forces in Thrace pushed the Ottoman armies to the gates of Constantinople. The Second Balkan War soon followed. Albania declared independence on 28 November.