Hundreds of thousands of Serbs celebrated their national day in the troubled Yugoslav province of Kosovo, but the region's ethnic Albanian majority boycotted the festival. In one of the biggest gatherings seen in Yugoslavia since it was founded in 1918, Serbs packed the plains around Pristina, the capital of Kosovo, for the 600th anniversary of a battle against Turkish invaders. The celebrants came from all over Yugoslavia, some from North America and Australia. Kosovo, the heart of medieval Serbia, is today an impoverished southern province adjoining Albania. The Orthodox Christian Serbs are a small minority there and claim they are harassed by the predominantly Muslim ethnic Albanians.