San Diego’s European history traces back to 1542 when Portuguese explorer Juan Rodríguez Cabrillo, sailing under the Spanish flag, became the first European to visit the region. Cabrillo claimed the bay for the Spanish Empire, naming it “San Miguel.” Decades later, in 1602, Sebastián Vizcaíno surveyed the harbor, Mission Bay, and Point Loma, renaming the area San Diego de Alcalá in honor of Saint Didacus.

Permanent European colonization began in 1769 with the arrival of Spanish contingents from New Spain and Baja California. Two seaborne expeditions—the San Carlos, led by Vicente Vila, and the San Antonio, commanded by Juan Pérez—arrived in San Diego Bay, while overland parties under Fernando Rivera and later Gaspar de Portolá advanced from the south. Missionary and chronicler Juan Crespí documented the early settlements, alongside figures like engineer Miguel Costansó and soldier Pedro Fages.

That same year, Portolà established the Presidio of San Diego on a hill overlooking the Kumeyaay village of Cosoy, marking California’s first European settlement. Shortly after, Mission San Diego de Alcalá, founded by Franciscan friars under Saint Junípero Serra, became the first of California’s iconic missions. The mission site faced challenges, including a Kumeyaay revolt in 1775, which forced its temporary relocation up the San Diego River. By 1797, the mission hosted over 1,400 native residents, becoming the largest settlement of its kind in Alta California.

Both the Presidio and Mission San Diego de Alcalá later earned recognition as National Historic Landmarks, anchoring the southern end of the historic El Camino Real mission trail and cementing San Diego’s place in California’s colonial history.