evidence: Portugal is one of the oldest nations in Europe having established its continental frontier as it is set today in 1297. Portugal has been an independent kingdom since 1143 when first Portuguese king Dom Afonso Henriques rebelled against his mother, Dona Teresa of Portugal Countess of Portugal. Teresa had rebelled against the Kingdom of Leon and was anointed Queen by the Pope although she was forced to accept Portugal as a country subject to Leon. After the amorous affair with Galician nobleman Fernando Perez de Traba took place her son Dom Afonso Henriques, with the backing of the Bishop and nobility defeated his mother in the battle of Sao Mamede in 1128 thus declaring independence from Leon. Portugal is located on the west side of the Iberian Peninsula, ideally positioned between Spain and the Atlantic ocean. Its geographic location along the Atlantic coastline is the reason why quickly became an ocean-bound country setting the stage for centuries of sea adventure and discoveries.