In the late 19th century, the Hatfields and McCoys were locked in a bloody, decades-long feud. The battle between the clans has been pop culture fodder since at least 1923, when Buster Keaton parodied the situation in his movie Our Hospitality.

But the event that launched the now-infamous conflict—which claimed the lives of 13 family members—has taken a backseat to the fact of its impressive longevity. What caused the bad blood in the first place?

A pig. Well, that’s how one of the stories goes, anyway. In 1878, Randolph McCoy accused Floyd Hatfield of stealing one of his hogs. The matter went to trial, with the star testimony coming from Bill Staton, a McCoy who married a Hatfield. Staton sided with Hatfield, and was later shot dead by Sam McCoy.

Adding fuel to the fire was the short-lived romance between Johnse Hatfield and Roseanna McCoy. After she became pregnant, McCoy moved in with the Hatfields, infuriating her family. But Romeo and Juliet they were not. Several months into the pregnancy, Johnse decided to move on with another McCoy—Nancy, Roseanna's cousin. Roseanna and Johnse's daughter died of the measles when she was 8 months old.

In 1882, three McCoys got into an election day fight with two Hatfields, which resulted in Ellison Hatfield being stabbed 26 times and shot in the back. Despite his horrific injuries, Hatfield didn’t immediately perish. Devil Anse, the head of the Hatfield clan and Ellison’s brother, vowed that he would not seek retaliation if his brother lived. When Ellison died three days later, Devil Anse found the three McCoy brothers who were responsible, dragged them into the woods, then blindfolded and shot them.

In 1888, the Hatfields struck again, ambushing the McCoy homestead and lighting it on fire in what became known as "The New Year's Day Massacre." Two were killed, including Alifair, a McCoy daughter who was caught in the crossfire. Her mother, Sarah, was badly beaten when she tried to help her dying daughter.

Ellison Mounts was hanged for Alifair’s death, and the feud seemed to settle down after that. But by the time all was said and done, at least 13 Hatfields and McCoys had died—all over a pig, it seems. Still, some historians believe that the hog was just a scapegoat. The real source of the ire, they say, was the Hatfields' Confederate leanings. (The McCoys considered themselves Unionists.)

A century later, the vendetta continued—sort of—in front of a live studio audience. For a 1979 Family Feud special, producers thought it would be funny to “litter the stage with bodies”—the Hatfield and McCoy teams received one appropriately attired mannequin for every match they won.