Purpose: ① Obtain gold and ivory from southern Africa; ②Allied with the Christian kingdom under King John to attack the Moors in North Africa.

After the 15th century, Western European countries gradually transitioned from the silver standard to the gold standard. However, the gold production in continental Europe is relatively low, and Europeans are increasingly feeling the shortage of gold. In order to purchase Eastern luxury goods, a large amount of European gold flowed to the East, which further promoted Westerners' yearning and pursuit of gold.

The 14th-century "The Travels of Marco Polo" provides exaggerated descriptions of the wealth of India, China and Japan. It describes that India and China are filled with gold and spices. Japan has so much gold that we don’t know how to use it. The roof is made of pure gold and the indoor floor is covered with gold bricks. These temptations led Europeans to risk their lives and cross the oceans to explore new routes to the East.

Spices were a rare and expensive commodity in Europe and had many practical uses. There is a lack of feed in the winter in Europe, and many cattle are slaughtered in the autumn. Europeans need to pickle a large amount of meat for storage in the winter. Oriental spices are good preservatives. Some spices have medical properties, such as cloves, which can numb nerves and relieve toothache.

In the Middle Ages, three trade routes from east to west were blocked. The area east of the Red Sea was controlled by Arab merchants, and the Mediterranean area was monopolized by Venice and Genoa in Italy.

In the mid-15th century, the Ottoman Turkish Empire emerged and occupied the Balkans and Asia Minor. Especially after occupying Constantinople in 1453, they controlled the traditional trade routes between the East and the West and imposed exorbitant taxes on European merchants, making the price of goods shipped to Europe 8 to 10 times higher than the original price. This prompted European countries to rush to open new routes and trade directly with the East.

In the Middle Ages, Portugal and Spain finally got rid of the rule of the Islamic Moors and became the most fanatical Christian countries in Western Europe.

In the 15th century, with the rise of the Ottoman Empire, which believed in Islam, Islam became more and more powerful, stimulating the Western Christian world's urgent need to spread Christianity.

Fanatic Christians hope to find out whether there are Christians outside the Muslim world, or other continents friendly to the Christian world, who can join forces to oppose the Muslims.

In the 15th century, the shipbuilding, navigation and drafting technologies of Portugal and Spain improved rapidly. They were able to build new, lightweight and safe multi-masted fast sailing ships, especially the use of triangular sails and the use of sails imported from China. The compass provides the most effective safety guarantee for ocean navigation.

In order to compete for colonies, the colonial countries, especially Portugal and Spain, had fierce conflicts from the beginning.

In the spring of 1493, Pope Alexander VI drew a dividing line west of the Azores Islands. The non-Christian lands and islands to the west of this line were explored and occupied by Spain, while those to the east were explored and occupied by Portugal.

In 1494, Portugal and Spain signed the Treaty of Tordesilia. The dispute between the two countries was resolved.

After that, Spain continued to send Columbus on three voyages to the Americas to open up colonies in the Americas. Portugal followed the African coast south into the Indian Ocean and opened up colonies in Asia.

Brazil was placed east of the dividing line, making Brazil the only Portuguese colony in South America.

In order to maintain the survival of its empire, Portugal began to colonize and plunder and sell black slaves. In the first 50 years of the 15th century, nearly 150,000 African slaves were imported.

In order to ensure new spice trade routes, Portugal occupied Mozambique and other places along the East African coast in the first decade of the 16th century, serving as supply stations and military strongholds for sailing to Asia. In the 16th century, Portuguese colonists plundered 276,000 kilograms of gold in Africa, as well as a large amount of ivory and slaves.

In Asia, in order to combat competition between Arabs and Turks, Portugal occupied Socotra, the gateway to the Red Sea, in 1506

In 1509, the Portuguese fleet fought a decisive battle with the combined Arab, Turkish and Indian fleets at Diu near India, almost destroying the combined fleet.

In 1510, Portugal established a viceroyalty in Goa on the Malabar Coast of India and sent a governor to rule.

In 1511, Portugal captured Malacca and controlled the throat of the Pacific and Indian Oceans. From then on, the trade in spices and other luxury goods between the East and the West was completely controlled by Portugal.

In 1513, Portugal began trade with China. In 1553, he seized Macau, China. The Portuguese even established a trading post on the Japanese island of Kyushu.

Driven by ignorant religious fanaticism and greed, the colonists committed heinous atrocities. They relied on superior weapons to carry out large-scale massacres, used fraudulent means to capture the Aztec and Inca empires, and melted all priceless cultural treasures into gold and silver nuggets and transported them back to the country.

The colonists also destroyed all valuable archives and destroyed Aztec and Inca temples, tombs and monuments, leaving no traces of Indian civilization and becoming one of the greatest catastrophes in human history.