Following the breakup of Yugoslavia in 1991, Slovenia and Croatia became independent countries. As the border between the countries had not been determined in detail prior to independence, several parts of the border were disputed, both on land and at the sea, namely in the Gulf of Piran.

The Permanent Court of Arbitration (PCA) is a non-UN intergovernmental organization headquartered at the Peace Palace, in The Hague, Netherlands. Unlike a judicial court in the traditional sense, the PCA provides administrative support in international arbitrations involving various combinations of States, State entities, international organizations and private parties. The cases span a range of legal issues involving territorial and maritime boundaries, sovereignty, human rights, international investment, and international and regional trade. The PCA is constituted through two separate multilateral conventions with a combined membership of 122 Contracting Parties. The PCA is not a United Nations agency, but has been a United Nations observer since 1993.