Answer:
A commercial airliner today would take about 50 hours to complete a turn around the maximum circumference of the Earth, the Equator, a distance of 40,000 kilometers. Five hundred years ago, however, little was known about the real size of our planet. The ancient Greeks were aware that the Earth is a sphere, and had even estimated how large it was; and Christopher Columbus had already set foot in Central America. However, the immensity of the Pacific Ocean was still outside the realm of knowledge, and the southern tip of South America had not even been sighted yet.
The Treaty of Tordesillas of 1494 had divided the globe into two zones for maritime exploration and trade. The Western zone, which embraced almost the entirety of the Americas, was set aside for Spain, while the eastern zone – including the western coast of Africa and the route to the Indian Ocean and Asia – was reserved for the Portuguese.
So, since Spain was barred from reaching Asia by means of the hitherto known route around the African continent, it now sought to find an alternative route to the Spice Islands—known today as the Moluccas.
The world, as carved up by the Treaty of Tordesillas.
That was when Fernão de Magalhães (Ferdinand Magellan), a Portuguese seaman who had spent eight years in the Portuguese Navy in the Indian Ocean and knew the area well, proposed an expedition to find a westward sea route to Asia. After being rebuffed by the King of Portugal, who already had his own exclusive African route, Magellan was granted a command by King Charles I of Spain—also known as the Holy Roman Emperor Charles V. The mission would turn out to be pioneering in the exploration of the globe.
