In order to elaborate a Convention on the legal status of the Caspian Sea, a special working group at the level of deputy foreign ministers was established in 1996 by the Caspian states. The agreement of the document lasted more than 20 years before its signing on 12 August 2018 by the heads of five Caspian states at the summit in Kazakhstan. During the years of approval of the convention (1996–2018) between the parties were held 51 meetings of the special working groups, more than ten meetings of foreign ministers and four presidential summits in 2002 in Ashgabat, in 2007 in Tehran, in 2010 in Baku and in 2014 in Astrakhan.