evidence: The British overseas territory of Gibraltar, a limestone outcrop on the southern tip of the Iberian peninsula, occupies a commanding position at the western gateway to the Mediterranean Sea. [...] Gibraltarians are British citizens. It is self-governing in all areas except defence and foreign policy and is home to a British military garrison and naval base. [...] 2020 - UK and Gibraltar leave the EU. UK and Spain agree in principle to a basis on which the UK and the EU could negotiate terms for Gibraltar to participate some aspects of the Schengen Agreement to ease border movements. The arrangements have not entered into force.