The history of Portugal dates back to the Early Middle Ages. In the 15th and 16th centuries, Portugal ascended to the status of a world power during Europe's "Age of Discovery" as it built up a vast empire, including possessions in South America, Africa, Asia, and Oceania. Over the following two centuries, Portugal kept most of its colonies, but gradually lost much of its wealth and status as the Dutch, English, and French took an increasing share of the spice and slave trades by surrounding or conquering the widely scattered Portuguese trading posts and territories.