There are no general rules determining how often Summits take place. Any participating State can propose a Summit. The decision to hold it, like all OSCE decisions, must then be taken by consensus. Between summits, decision-making and governing powers lie with the Ministerial Council.
The fundamental document of the Conference on Security and Co-operation in Europe (CSCE), the Helsinki Final Act, was adopted by the original 35 participating States at the first CSCE Summit, which took place in Helsinki from 30 July-1 August 1975.
The second CSCE Summit, held in Paris in November 1990, laid the foundations of the institutionalization process that transformed the CSCE into today’s OSCE. Five subsequent Summits were held in Helsinki (1992), Budapest (1994), Lisbon (1996), Istanbul (1999) and Astana (2010). Each of these events produced declarations and documents that are important milestones in the history of the Organization.
Summits are preceded by Review Conferences to review the entire range of activities within the organization and to prepare a decision-oriented document to be adopted at the Summit itself. Review conferences are operational and of short duration.