Honey has been prized for thousands of years as food, medicine and a natural sweetener.

But more than 2,000 years ago, it also became an unlikely weapon.

Around 67 BC, during the Third Mithridatic War, Roman soldiers marching through what is now northeastern Turkey came across what appeared to be an abandoned supply of honey. They ate it.

Within hours, many became dizzy, confused, nauseated and too weak to fight. Waiting nearby, local tribes allied with King Mithridates VI attacked while the Romans were incapacitated, turning an ordinary meal into one of history's most ingenious military ambushes.

The honey's surprising power came from the flowers.

It had been made from the nectar of certain rhododendron species that contain grayanotoxins, naturally occurring compounds that affect the heart and nervous system. Even small amounts can cause a dramatic drop in blood pressure, a dangerously slow heartbeat, dizziness and vomiting.

This unusual honey, known as mad honey, is still produced today in parts of Turkey and Nepal. 

Although many rhododendron species around the world contain grayanotoxins, the toxic honey associated with history's famous ambush comes primarily from a handful of species native to the Black Sea region. Today, mad honey is sometimes sold in small quantities as a traditional remedy, but because toxin levels vary naturally from one batch to another, consuming too much can cause serious poisoning.

Very Cool Fact: The Roman ambush wasn't the first recorded encounter with mad honey. Around 401 BC, the Greek historian Xenophon described thousands of soldiers becoming so sick after eating wild honey near the Black Sea that they staggered as though drunk and were unable to stand. Fortunately, no enemy attacked before they recovered a day or two later.