Also known as the Madrid Quartet and the Middle East Quartet. Made up of the United States, European Union, United Nations and Russia. Their involvement in the Middle East peace process began following a meeting in Madrid, Spain in April 2002. Representatives of each Quartet member met to discuss concerns over the Israeli-Palestinian conflict and issue a joint-statement calling for a cease-fire. According to the April 10, 2002 statement, the Quartet “agreed on the need to keep the situation in the Middle East under review...at the principal’s level through regular consultations” while maintaining special envoys on the ground “to assist the parties in reaching an end to confrontation and resumption of political negotiations.” See “Remarks…” 10 April 2002. UNISPAL. 31 October 2011. http://unispal.un.org/UNISPAL.NSF/0/4808D2E68A33B35385256B970062DEAF.  http://www.justvision.org/glossary/quartet