The system has been in place since the beginning of agriculture.

As soon as men abandoned the life of wandering, tribal hunters to till the soil they needed to predict the seasons. Such knowledge was required in order to know when to plant, when to expect floods in fertile valleys, when to expect rainy seasons, and so on. Months of backbreaking work were wasted by the unavailability of the calendar, a convenience we take for granted. The men who first studied and grasped the regularities of sun, moon, and stars that presage the seasons had a valuable commodity to sell and they milked it to the fullest at the expense of their credulous fellowmen. The occult priesthoods of early astronomers and mathematicians such as the designers of Stonehenge, convinced their subjects that they alone had contact with the gods, and thus, they alone could assure the return of planting seasons and weather favorable to bountiful harvests. The staging (predicting) of solar and lunar eclipses was particularly effective in awing the community. The general success resulting from following the priesthood's tilling, planting, nurturing, and harvesting timetables insured the priesthood's power. Today's Christmas holiday season continues the tradition set by ancient priesthoods, who conducted rituals on the winter solstice to reverse the retreat of the sun from the sky. Their invariable success was followed by wild celebrations. Popular knowledge of seasonal regularities was discouraged by every manner of mysticism and outlandish ritual imaginable. Failures in prediction were blamed on sins of the people and used to justify intensified oppression. For centuries people who had literally no idea of the number of days between seasons and couldn't count anyway, cheerfully gave up a portion of their harvests, as well as their most beautiful daughters, to their "faithful servants" in the priesthoods.

http://rexresearch.com/articles/ocultech.htm