Francisco Franco continued to insist that Gibraltar was territorially integral to Spain and, "in a fit of diplomatic pique",[1] ordered the closure of the border in 1969.
This natural tendency of the two populations to interact demonstrated the artificial division that had been created and continued to exist so long as Britain retained possession of Gibraltar.
Instead, he demanded the immediate return of Gibraltar, initiated a newspaper campaign in which the entire population was characterised as criminals and individuals of dubious moral character, and imposed border restrictions that caused real hardship on the inhabitants.
[2]A diplomatic stalemate persisted until after the death of Franco, when Margaret Thatcher's government initiated a political process that resulted in the Lisbon Agreement.
[3] Its preamble stated: The British and Spanish governments, desiring to strengthen their bilateral relations and thus to contribute to Western solidarity, intend, in accordance with the relevant United Nations Resolutions, to resolve, in a spirit of friendship, the Gibraltar problem.