Coat of arms of Portugal I became a dragon, probably associated to the adoption of Saint George as the patron saint of Portugal. Until the 17th century, the dragon was represented in "or", but since then, it started to be represented in "vert". This change of color was probably due to the ascension to the throne, in 1640, of the House of Braganza, which had the green as its livery color, this also becoming the national color of Portugal. During the period of the House of Braganza, two dragons "vert" became frequently used as the supporters of the Portuguese Royal shield. Other of the external
Portugal son-in-law of Ferdinand I of Portugal, claimed the throne of Portugal. A faction of petty noblemen and commoners, led by John of Aviz (later King John I of Portugal) and commanded by General Nuno Álvares Pereira defeated the Castilians in the Battle of Aljubarrota. With this battle, the House of Aviz became the ruling house of Portugal. Portugal spearheaded European exploration of the world and the Age of Discovery. Prince Henry the Navigator, son of King João I, became the main sponsor and patron of this endeavour. During this period, Portugal explored the Atlantic Ocean, discovering several Atlantic archipelagos like