In 1492, Columbus landed in today's Dominican Republic, believing he had reached Asia.
He was the first European to discover the Americas.
This discovery marked a huge turning point for the Spanish, who went on the colonise the Americas and become the most powerful kingdom in Europe.
Around 1510, the Spanish founded the first settlement in Central America and discovered the Isthmus of Panama, a land passage connecting the Atlantic and Pacific, which could facilitate the movement of trade and people.
A few years later they conquered the Aztec and Inca Empires.
California remained untouched by the Europeans for many years, separated from the Europeans by mountains, jungles and deserts.
The closest European port to California was Acapulco, which actively traded with the Philippines (also a Spanish colony).
Massive galleons, called the Manila galleons, sailed back and forth from America to the Philippines, over several months, carrying spices and porcelain in exchange for gold.
The Spanish were keen to find a faster route connecting America to Asia.
A popular thought was that there might be a passage to the North - so a navigator, Cabrillo, sailed off to explore, reaching as far as Point Reyes and missing the San Francisco Bay because of the fog.
There are many references to him across the state, including schools and the Cabrillo Highway.
A replica of his ship was built in San Diego in 2015.
Several other maritime expeditions followed.
The English pirate Sir Francis Drake sailed up the entire west coast of the Americas and reached Point Reyes in California, where Drake's Cove is now named after him.
Another sailor, Soromenho, sailed across from the Philippines and hit California around Trinidad. His ship sunk but he navigated a large canoe back down to Mexico, also missing San Francisco Bay because of the fog.
Finally a third sailor, Vizcano, sailed from Mexico and reached Cape Mendocino, naming multiple sites along the way : San Diego Bay, Santa Barbara, the Channel Islands, Point Lobos, Monterey Bay...
Fun fact : he anchored in Point Reyes on the Epiphany ("the day of the 3 kings"), which gave rise to the name Point Reyes ("reyes" = "king").
After that, the Europeans halted exploration for about 150 years, as European affairs dominated Spanish attention.