Alexander the Great conquered the Persian Empire from 336 to 323 BC after being tutored by Aristotle and inheriting the throne after his father's assassination. According to Pagden, Alexander's ambition was to unite Asia and Europe by providing a space for diverse peoples to coexist in peace. Portugal became a key supporter of 15th century maritime exploration, establishing a trade empire from Africa to India and China under explorers like Vasco da Gama. Christopher Columbus subsequently sailed for Spain on four voyages from 1492 to 1504, becoming the first to connect Europe and the Americas.