In the late 1400s, European exploration boomed, driven by Christian zeal and the lucrative spice trade. Spices from the Far East were extremely valuable, and Portugal dominated the route to the Spice Islands by 1518. Spain, seeking its own route, accepted Ferdinand Magellan's bold plan to sail west around the New World to reach the Spice Islands, based on the widely accepted idea that the Earth was round.

King Charles I of Spain supported Magellan's expedition of 270 crew and five ships, which set sail on September 20, 1519. After crossing the Atlantic and trading with local tribes in Brazil, Magellan faced a mutiny during winter storms. He ruthlessly suppressed it, executing and marooning some of the Spanish officers. As they continued south, one ship was wrecked, and another deserted. However, Magellan discovered the 350-mile Strait of Magellan and entered the Pacific Ocean, which he named for its peaceful appearance.

The Pacific Ocean was much larger than anticipated, leading to severe supply shortages. The crew suffered from hunger, drinking putrid water, and 19 died of scurvy. After 99 days, they reached Guam in the Mariana Islands but had to leave without fresh provisions after a conflict with the Islanders. A week later, they became the first Europeans to reach the Philippines, where they feasted on local produce.

In the Philippines, Magellan formed an alliance with a local ruler on Seibu who converted to Christianity. Magellan agreed to help this ruler against a rival chief, Lapu-Lapu, on Mactan. Despite superior weapons, Magellan and his men were vastly outnumbered and driven back into shallow water, where Magellan was killed while trying to reach the boats. Following his death, former allies on Cebu ambushed and killed 30 of Magellan's crew. With only enough men for two ships, they burned the Concepción and continued their search for the Spice Islands.

After visiting Brunei on Borneo, they finally reached the Spice Islands (Maluku Islands) more than two years after leaving Spain. They traded all their possessions for cloves, but the Trinidad sprang a leak and had to stay for repairs, with its crew later captured by the Portuguese. The Victoria, the last and smallest ship, captained by Juan Sebastian Elcano, sailed west for home, facing nine weeks of battling headwinds and starvation around the Cape of Good Hope.

On September 8, 1522, almost exactly three years after their departure, the exhausted crew of the Victoria cast anchor in Seville, Spain. Only 18 of the original 270 crew members survived. This incredible feat marked the first circumnavigation of the world, providing conclusive proof that the Earth was a sphere and offering a new understanding of its vastness. This achievement was not repeated for another 58 years until Francis Drake's voyage.