History.com: How Portugal's Seafaring Expertise Launched the Age of Exploration

In the 15th century, a small kingdom with a population of approximately 1 million launched the era of maritime exploration that would transform the world. Portugal turned to the boundless Atlantic Ocean as its only outlet to the wider world, exploring the Canary Islands off the northwestern coast of Africa. Rival Spain would later end up conquering the Canaries, but the Portuguese had already seized the global advantage when it came to shipbuilding, navigation and map-making. The 15th century dawned, Portugal under the ambitious King John I turned its sights toward Morocco, the Muslim stronghold seen as the gateway to the gold, spices and other untold riches in Africa and beyond.