On May 20, Godoy finally entered Portugal; this incursion was a precursor of the Peninsular War that would engulf the Iberian Peninsula. The Spanish army quickly penetrated the Alentejo region in southern Portugal and occupied Olivença, Juromenha, Arronches, Portalegre, Castelo de Vide, Barbacena and Ouguela without resistance. Campo Maior resisted for 18 days before falling to the Spanish army, but Elvas successfully resisted a siege by the invaders. An episode which occurred during the siege of Elvas accounts for the name, "War of the Oranges": Godoy, celebrating his first experience of generalship, plucked two oranges from a tree and immediately sent them to Queen Maria Luisa of Spain, mother of Carlota Joaquina and supposedly his lover, with the message: