**Before splitting, Kosovo was a province of Yugoslavia.**

**Explanation:**

Yugoslavia, also known as the Federal Republic of Yugoslavia, was a country in Southeast Europe that existed from 1945 to 2003. It was composed of six socialist republics, including Kosovo as one of its provinces. Here is a detailed explanation of the answer:

1. **Yugoslavia:** After World War II, Yugoslavia was formed as a federation of six socialist republics: Bosnia and Herzegovina, Croatia, Macedonia, Montenegro, Serbia, and Slovenia. Kosovo was initially an autonomous province within Serbia, which was one of the republics.

2. **Autonomy:** In 1946, Kosovo became an autonomous province within the Socialist Republic of Serbia, which was a constituent republic of Yugoslavia. This autonomy allowed Kosovo to have its own government and institutions, while still being a part of Yugoslavia.

3. **Tensions and Conflict:** In the late 1980s and early 1990s, tensions between different ethnic groups within Yugoslavia, particularly between Serbs and Albanians in Kosovo, escalated. Serbian leader Slobodan Milosevic revoked Kosovo's autonomy in 1989, leading to widespread protests and resistance from the ethnic Albanian majority.

4. **Breakup of Yugoslavia:** The breakup of Yugoslavia began in the early 1990s, as the individual republics sought independence. Slovenia, Croatia, Bosnia and Herzegovina, and Macedonia declared independence, leading to violent conflicts and wars. Kosovo also sought independence during this period.

5. **Kosovo War:** The Kosovo War occurred from 1998 to 1999, primarily between the forces of the Federal Republic of Yugoslavia (Serbia and Montenegro) and the Kosovo Liberation Army (KLA). The war resulted in significant human rights abuses and displacement of the population.

6. **UN Administration:** After the war, Kosovo came under the administration of the United Nations Mission in Kosovo (UNMIK) and was governed by the UN until its declaration of independence in 2008.

In conclusion, Kosovo was a province of Yugoslavia before it split. The tensions and conflicts within Yugoslavia, including the revocation of Kosovo's autonomy and the Kosovo War, eventually led to Kosovo seeking independence.