evidence: In 1704, Gibraltar was taken over by a British-Dutch force during the War of Spanish Succession and in 1713 it was ceded to Great Britain with the Treaty of Utrecht. From 1779 to 1783 attempted to take Gibraltar back during the Great Siege of Gibraltar. It failed and Gibraltar eventually became an important base for the British Royal Navy in conflicts like the Battle of Trafalgar, the Crimean War, and World War II. In the 1950s Spain again began trying to claim Gibraltar and movement between that region and Spain was restricted. In 1967 the citizens of Gibraltar passed a referendum to remain a part of the United Kingdom and as a result, Spain closed off its border with the region and ended all foreign relationships with Gibraltar. In 1985, however, Spain reopened its borders to Gibraltar. In 2002 a referendum was held to establish shared control of Gibraltar between Spain and the UK but Gibraltar's citizens rejected it and the area remains a British overseas territory to this day. Today Gibraltar is a self-governing territory of the United Kingdom and as such its citizens are considered British citizens.