evidence: Kosovo declared itself a sovereign state 15 years ago. Which countries recognise it, and how are its relations today with Serbia? [...] Kosovo is a southeastern European country bordered by Albania, North Macedonia, Montenegro and Serbia. It has a population of 1.9 million people, and ethnic Albanians form 93 percent of the population while Serbs make up about 6 percent of the population. [...] Kosovo was once part of Yugoslavia, which was formed after World War I in 1918. It was made up of six Slavic groups, and its official language was Serbo-Croatian.