Chocolate residue found in several jars from the site of Puerto Escondido in Honduras, from around 1100 BC, is the earliest evidence to date of the use of cacao. The evidence found indicates that the earliest use of cacao seems to have been as an alcoholic beverage. Slightly later, around 600-400 BC there are traces from jars in Belize. An early Classic (460-480 A.D.) period Maya tomb from the site of Rio Azul, Guatemala, had vessels with the maya glyph for cacao on them and had residue of a chocolate drink. The Aztecs associated chocolate with Xochiquetzal, the goddess of fertility. In the Americas, chocolate was consumed in a bitter and very spicey drink called xocoatl, often seasoned with vanilla, chile pepper, and achiote (which we know today as annatto). Xocoatl was believed to fight fatigue, a belief that is probably attributable to the theobromine content. Other chocolate drinks combined it with such edibles as maize gruel (which acts as an emulsifier) and honey. Chocolate was also an important luxury good throughout pre-Columbian Mesoamerica, and cacao beans were often used as currency. For example, the Aztecs used a system in which one turkey cost one hundred cacao beans and one fresh avocado was worth three beans. South American and European cultures have used cocoa to treat diarrhea for hundreds of years. All of the areas that were conquered by the Aztecs that grew cacao beans were ordered to pay them as a tax, or as the Aztecs called it, a "tribute". Until the 1500s, no European had ever heard of the popular drink from the Central and South American peoples.[12] Jose de Acosta, a Spanish Jesuit missionary who lived in Peru and then Mexico in the later 16th century, wrote of it: Loathsome to such as are not acquainted with it, having a scum or froth that is very unpleasant taste. Yet it is a drink very much esteemed among the Indians, where with they feast noble men who pass through their country. The Spaniards, both men and women, that are accustomed to the country, are very greedy of this Chocolate. They say they make diverse sorts of it, some hot, some cold, and some temperate, and put therein much of that "chili"; yea, they make paste thereof, the which they say is good for the stomach and against the catarrh. Christopher Columbus brought some cocoa beans to show Ferdinand and Isabella of Spain, but it was Spanish friars who introduced it to Europe more broadly. It wasn't until the Spanish conquest of the Aztecs that chocolate could be imported to Europe, where it quickly became a court favorite. The first recorded shipment to Europe for commercial purposes was in a shipment from Veracruz to Sevilla in 1585. It was still served as a beverage, but the Europeans added sugar and milk to counteract the natural bitterness and removed the chili pepper, replacing it with another Mexican indigenous spice, vanilla. http://en.wikipedia.org/wiki/History_of_chocolate

probably cause it tastes good

They didn't "invent" it. The first chocolate was smoked with tobacco to give it a more mellow flavour.