Spain
the Iberian peninsula was characterized by a variety of
independent kingdoms prior to the Muslim occupation that began in
the early 8th century AD and lasted nearly seven centuries; the
small Christian redoubts of the north began the reconquest almost
immediately, culminating in the seizure of Granada in 1492; this
event completed the unification of several kingdoms and is
traditionally considered the forging of present-day Spain
Sri Lanka
4 February 1948 (from UK)
Sudan
1 January 1956 (from Egypt and UK)
Suriname
25 November 1975 (from Netherlands)
Svalbard
none (territory of Norway)
Swaziland
6 September 1968 (from UK)
Sweden
6 June 1523 (Gustav VASA elected king)
Switzerland
1 August 1291 (founding of the Swiss Confederation)
Syria
17 April 1946 (from League of Nations mandate under French
administration)
Tajikistan
9 September 1991 (from Soviet Union)