The Central European Initiative (CEI) is the oldest and largest intergovernmental forum for regional cooperation in Europe, with an observer status in the General Assembly of the United Nations.

Its origin lies in the creation of the Quadrangolare in Budapest on 11 November 1989, the founding fathers of which were Austria, Hungary, Italy and the Socialist Federal Republic of Yugoslavia. On that occasion, the Ministers for Foreign Affairs of the four founding members adopted a joint declaration stating the readiness of their Governments to strengthen good-neighbourly relations and to develop manifold cooperation among their respective countries.

In 1990, Czechoslovakia was admitted and the Initiative was renamed Pentagonale; in 1991, with the admission of Poland, it became Hexagonale.

A number of new countries were admitted in 1992, at which time it was decided to rename the organisation the Central European Initiative. The expansion of the Initiative continued in 1993, 1996 and from 2000 to 2006, with the admission of its last country, Montenegro, increasing the number of Member States to eighteen.

In the meantime, several CEI Member States became European Union Member States, also thanks to the CEI’s contribution in terms of cooperation for the social and economic development of the area.

The CEI Secretariat is based in Trieste.