1519 CE
King Montezuma regularly drank a cocoa-based beverage

In 1519, Spanish conquistador Hernando Cortez landed on the east coast of Mexico and led his troops inland toward the capital, Tenochtitlan, where they were received by King Moctezuma. A member of crew reflected on their first chocolate experience:
“[From time to time the men of Montezuma’s guard] brought him, in cups of pure gold a drink made from the cocoa-plant, which they said he took before visiting his wives. We did not take much notice of this at the time, though I saw them bring in a good fifty large jugs of chocolate, all frothed up, of which he would drink a little. As soon as the great Montezuma had dined, all the guards and many more of his household servants ate in their turn. I think more than a thousand plates of food must have been brought in for them, and more than two thousand jugs of chocolate frothed up in the Mexican style”

Source: Dillinger, Teresa L. (2000). Food of the Gods. The Journal of Nutrition.

Drugs: Cacao (cocoa, chocolate)
Regions: Mexico