Although discovered early in the sixteenth century by adventurous Spaniards, no serious attempt was made at settlement of any portion of the territory now included in the boundaries of California until the year 1769, when Father Junipero Serra arrived at the Bay of San Diego. Then followed a half century constituting the Mission Period of California history, during which Spanish Governors and Franciscan Friars ruled the land. Inspired more by religious zeal than by lust of conquest, or hope of gain, the Spanish Padres planted a chain of missions extending from San Diego to the Bay of San Francisco. At these missions, consisting often, at the beginning, of nothing more than a rude cross and altar, with some miserable make-shift of tent or huts as protection from the heat of summer and the cold of winter, the faithful priests labored to convert the surrounding Indians. They tried to make of them not alone good Catholics, but good farmers, and vineyardists, and according to the need of the time, capable carpenters and builders. As the result of their labors a long period of simple prosperity was enjoyed at the missions. Buildings were erected that still delight the traveler. They were for the most part of Moorish architecture, built of adobe, painted white, with red-tile roofs, long corridors and ever the secluded plaza where the friar might tell his beads in peace. Around the missions, some twenty in number, lying a day's journey apart between the southern and the central bay, Indian workers cultivated immense fields of grain, choice vineyards, olive orchards and orange groves; great herds of horses, cattle, and sheep were cared for, and the women became adept at weaving and spinning. Nor were the Spanish Governors idle. They encouraged the immigration of settlers both from the mother country and Mexico by a most liberal policy, assisting the newcomer to build a home, acquire stock, and establish himself in a country where there was an abundance of game, and where the earth yielded her bounty with the minimum of labor. Thus in the half century between 1770 and 1820, these Pius Padres laid the foundations of California, as they believed securely, after Catholic and Spanish tradition.