Why did Greek, Serbian, and Montenegrin armies enter Albanian territories in 1912?

In October 1912, Greek, Serbian, and Montenegrin armies entered Albanian territories as part of the First Balkan War. These nations, organized into the Balkan League, declared war on the Ottoman Empire with the primary objective of expelling the Turks from the Balkans and partitioning the region's territories among themselves.123

The invasion was driven by several key factors:

• Territorial Ambitions: The Balkan allies sought to divide the Albanian districts of the Ottoman Empire among their own states.3
• Opposition to Autonomy: Neighboring Balkan states were alarmed by the prospect of [Albanian autonomy], which had been gaining momentum following successful Albanian uprisings against the Young Turks between 1910 and 1912.13
• Strategic Interests: Serbia, in particular, had extensive claims on Albanian territory and desired a direct outlet to the sea.45

In response to this occupation and the threat of national annihilation, Albanian delegates led by Ismail Qemal met in Vlorë and issued the Vlorë proclamation on November 28, 1912, declaring Albania an independent state.13