This excerpt is best description on Serb feelings for Kosovo:
"Actually, this fierce battle on the Field of Blackbirds (the meaning of the name of Kosovo) ended in a draw, with both the Serbian Prince Lazar and the Turkish Sultan Murat being killed in battle. But the weakened Serbia, pressed from the north by the rival Hungarian kingdom, never recovered. It is then, as the story goes, that the bright red peonies that bloom by the millions each year on Kosovo's plains made their appearance, growing out of the soil consecrated by the spilt Christian blood."
Isnt that also called St Vitus Day? (June 28th 1389 IIRC).