The first recorded evidence of chocolate as a food product goes
back to Pre-Columbian Mexico. The Mayans and Aztecs were known
to make a drink called "Xocoatll" from the beans of the cocoa tree. In
1528, the conquering Spaniards returned to Spain with chocolate still
consumed as a beverage. A similar chocolate drink was brought to a
royal wedding in France in 1615, and England welcomed chocolate in
1662. To this point "chocolate" as we spell it today, had been spelled
variously as "chocalatall, "jocolatte", "jacolatte", and "chockelet.11

In 1847, Fry & Sons in England introduced the first "eating chocolate,"
but did not attract much attention due to its bitter taste. In 1874,
Daniel Peter, a famed Swiss chocolateer, experimented with various
mixtures in an effort to balance chocolates rough flavor, and eventually
stumbled upon that abundant product -- milk. This changed everything
and chocolate's acceptance after that was quick and enthusiastic.

From: Chocolate: The Consuming Passion by Sandra Boynton.
Workman Publishing: New York, 1982

Time Life's Food of the World: Latin American Cooking states that
the first Spaniards meeting Montezuma, the Aztec emperor, noted
several types of chocolate drinks being drunk at court, including one
that was flavored with honey, ground up dried flowers and vanilla pods.
It didn't say which flowers.