Background Capture of Gibraltar
at start of war of spanish succession portugal nominally ally of bourbons: france under louis xiv, , spain under grandson, philip v. although not belligerent, portugal s harbours closed enemies of bourbon powers – principally vessels of england , dutch republic. however, following anglo-dutch naval victory @ vigo bay in 1702 balance of naval forces had swung in favour of grand alliance. having ability cut off portugal s food supplies , trade (particularly gold brazil) not hard allied diplomats induce king peter ii sign methuen treaties of may 1703 , join alliance. once peter ii had committed himself war alliance fleets gained access portugal s harbours, in particular port of lisbon. in return allegiance peter ii had demanded military , financial aid , territorial concessions in spain; had asked alliance send lisbon emperor leopold s younger son, charles – alliance s habsburg candidate spanish throne – demonstrate earnestness of support. known supporters charles iii of spain, young pret...