The Spanish Empire lasted from the time of Christopher Columbus to c. 1900 and in that time was the starting point for many of the famous European explorers and the home of an empire that, for hundreds of years, ruled most of the Americas.
For hundreds of years, the Moorish people (Muslims from Northwest Africa) controlled parts of Spain and, therefore, ruled over the Spanish people. Eventually, however, the Spanish pushed the Moorish people off the European continent, and the Spanish then were able to focus on exploring new lands. The Spanish government supported Christopher Columbus' voyage to the west, which resulted in the discovery of the North American continent (however, the Vikings and, of course, the Native Americans had long since discovered North America.)
The Spanish took advantage of Columbus' discovery and the posterior circumnavigation by Ferdinand Magellan, and quickly got large portions of the Americas and the Pacific islands under control; the British and the French would lag behind the Spanish until the 1600s. Spain's empire became huge, and remained so until the early 1800s, when Latin America became independent from Spanish rule.
However, a mere look at a map can be deceiving and while the Spanish Empire did indeed declare (and in many case have said declarations recognized by other European powers) rule over vast swaths of territory, often they just replaced the very top layer of native society with Spaniards and only slowly spread their rule and the Spanish language further, sometimes even relying on Native languages like Nahuatl in Mexico or Guaraní in what is today Paraguay. Some countries had to engage in "nation building" or even outright conquest of de facto indigenous polities even after independence. Nicaragua only got control of Caribbean Nicaragua a hundred years after the Spanish Empire lost control over Central America and Chile only subdued its southernmost parts after independence.
Finally, the Spanish Empire largely ceased to exist following the Spanish-American War, when much of Spain's final colonial possessions were surrendered to the United States.
Regions once part of the Spanish Empire
- South America, excluding Brazil, Guyana, Suriname and French Guiana
- Central America, excluding Belize, and parts of the Caribbean (Cuba, the Dominican Republic and Puerto Rico)
- Equatorial Guinea, the only Spanish colony in Africa other than the Canary Islands and the ports of Ceuta and Melilla
- Western Sahara, one of Spain's last colonies whose "messy divorce" with the mother country — and subsequent Moroccan invasion — created an enduring conflict that while "frozen" presents problems for mapmakers to this day
- Florida, Louisiana, Texas and quite a few southwestern states in the United States were once part of the Spanish Empire; some eventually were part of the Mexican Empire before the 1846-1848 Mexican-American War.
- The Netherlands and Portugal