On 22 October 1999, the Security Council established UNAMSIL
to cooperate with the Government and the other parties in
implementing the Lome Peace Agreement and to assist in the
implementation of the disarmament, demobilization and reintegration
plan. On 7 February 2000, the Council revised UNAMSIL's mandate. It
also expanded its size, as it did once again on 19 May 2000 and on
30 March 2001.
UNAMSIL successfully completed its mandate in December 2005. It was succeeded by a new mission—the United Nations Integrated Office for Sierra Leone (UNIOSIL)—established by the Security Council to help consolidate peace in the country.