The tag line of the film was "This is the story of the making ...and the forging...of California...when men chose gold or God...the sword or the Cross".

Its religious advisor, peace-loving missionary Father Junípero Serra, wishes to establish good relations with the local natives and to build a string of missions, beginning at San Diego Bay.

He is unexpectedly aided when Portola's prideful second in command, Lt. Jose Mendoza, saves the life of Matuwir, the grandson of the local chief.

But when a supply ship fails to appear and the expedition prepares to return to Mexico a failure, Mendoza betrays Matuwir's sister Ula, whom he has seduced, resulting in her accidental death by a fall from a cliff.

"[3] Film rights were bought by 20th Century Fox who in June 1952 announced Charles Brackett would produce and John C Higgins would write the script.