A brief history:
It's hard to pin down exactly when chocolate was born, but it's clear that it was cherished from the start. For several centuries in pre-modern Latin America, cacao beans were considered valuable enough to use as currency. One bean could be traded for a tamale, while 100 beans could purchase a good turkey hen, according to a 16th-century Aztec document.
Both the Mayans and Aztecs believed the cacao bean had magical, or even divine, properties, suitable for use in the most sacred rituals of birth, marriage and death. According to Chloe Doutre-Roussel's book The Chocolate Connoisseur, Aztec sacrifice victims who felt too melancholy to join in ritual dancing before their death were often given a gourd of chocolate (tinged with the blood of previous victims) to cheer them up.