San Diego 200th Anniversary banner, 1769 - 1969, 10 x 13 inches, with images of a Spanish explorer and Friar Junipero Serra. Spanish explorer Juan Cabrillo discovered San Diego Bay in 1542, and the historic fort, El Presidio Real de San Diego, was established in May 1769 by Gaspar de Portola. Fr. Serra founded Mission San Diego de Alcala in July 1769, the first Franciscan mission in the Las Californias Province. This was donated to the Mayor's office by the family of Bob Schremp of Bellflower, California.