1. Adolf and Rudolf Dassler

After the Dassler brothers started a shoe company out of their mother’s home in the 1920s in Herzogenaurach, Germany, their business got a big boost when U.S. track-and-field gold medalist Jesse Owens sported the Dassler’s footwear at the 1936 Olympics in Berlin. However, for reasons that remain a mystery, the siblings’ relationship soured. One incident said to have contributed to its demise, according to some sources, occurred during World War II when Adolf, upon entering a bomb shelter occupied by Rudolf and his family, said, “The dirty bastards are here again.” Adolf supposedly was talking about Allied bombers but Rudolf believed his brother was insulting his family. In the late 1940s, the tensions between the Dasslers led them to launch competing athletic shoe manufacturers: Adolf dubbed his Adidas (from his nickname, “Adi,” and the first three letters of his last name) while Rudolf’s became known as Puma (he initially called it “Ruda,” based on letters from his first and last name). The brothers constructed factories on opposite sides of the river in Herzogenaurach, and the rivalry grew so intense that some local shops catered solely to Adidas or Puma employees and it was frowned upon for a worker from one company to wed someone from the other firm.

2. The Pleasant Valley War

During the last part of the 19th century, two Arizona ranching families, the Grahams and Tewksburys, engaged in a long-running, bloody battle that resulted in the deaths of 20 or more people, by some estimates. The exact details of how the so-called Pleasant Valley War was ignited in the early 1880s are unknown, but accusations of cattle-rustling likely played a role. The feud came to a violent end with the 1892 murder of Tom Graham, the last survivor of his family involved in the feud, who was ambushed by Ed Tewksbury in Tempe, Arizona. Tewksbury spent a short time behind bars before being freed.

3. Sterling and Stephen Clark

Heirs to the Singer sewing machine fortune, the Clark brothers each assembled art collections considered to be among the greatest of the 20th century; however, a 1923 fistfight between the two over their inheritance resulted in a nearly 40-year feud. The pair’s grandfather, Edward Clark, was a lawyer who established a sewing machine company with inventor Isaac Merritt Singer in the 1850s. When Edward Clark (who also developed real estate in New York City, including the famous Dakota building) died in 1882 he left an estate worth a reported $50 million. Sterling Clark was an adventurer who served in the U.S. Army in the Philippines and China, where he fought in the Boxer Rebellion. In 1919, he wed a French actress with an illegitimate child; several years later, when he attempted to change the terms of the family trust so his wife would inherit his share of the wealth rather than his siblings (there were four brothers in all), Stephen, a businessman, prevented him from doing so. For the rest of their lives, Stephen (who founded the National Baseball Hall of Fame in Cooperstown, NY, where the brothers were born) and Sterling (who started the Clark Art Institute in Williamstown, MA) had almost no contact with each other.

4. Sutton-Taylor Feud

The Sutton-Taylor feud, referred to as Texas’s bloodiest, kicked off following the U.S. Civil War and didn’t draw to a close, in court, until the 1890s. On one side of the trouble were William Sutton and his associates, who included law enforcement officials, and on the other side were brothers and former Confederates Creed and Pitkin Taylor, along with their relatives and such friends as the outlaw John Wesley Hardin. Like a number of other feuds, it’s unclear exactly what caused this one, although there’s speculation it was sparked by such events as the murder of two Union soldiers by a member of the Taylor clan, and the fatal shooting by law enforcement of Taylor relatives suspected of being horse thieves. The fighting went on from the late 1860s well into the 1870s and left an unknown number of men dead on each side, including William Sutton and Pitkin Taylor. The last court case related to the feud was resolved in the 1890s.

5. Boyce-Sneed Feud

In 1911, a Texas woman, Lena Snyder Sneed, told her husband, John Beal Sneed, she planned to leave him for another man, Al Boyce Jr. After hearing his wife’s confession, Beal Sneed had her committed to a sanitarium. With the Boyce’s help, Lena soon escaped the institution and the pair fled to Canada, where they were arrested. Lena eventually was sent back to her husband, while Boyce’s father, Albert Sr., a former manager of the massive XIT Ranch, helped to get the kidnapping charges against his son dropped. In January 1912, Beal Sneed shot and killed Boyce’s father in a Ft. Worth hotel lobby. The high-profile court case ended in a mistrial after the jury was deadlocked in favor of acquittal. That March, Beal Sneed’s father was gunned down, and Beal Sneed believed the killer was linked to the Boyces. In September, Beal Sneed fatally shot Al Boyce Jr. outside a church in Amarillo. Sneed went on to be acquitted in the slayings of both Boyces. (Asked by the press why Beal Sneed was acquitted of killing Albert Jr., a juror said, “because this is Texas” where a man is allowed to “safeguard the honor of his home.”) In 1922, Beal Sneed was sentenced to two years in prison for bribing a juror in a lawsuit. When he got out, he shot a man who had killed his son-in-law. Beal Sneed’s victim survived, and later tried to murder Beal Sneed (who went on to be acquitted of shooting the man). Beal Sneed and Lena remained married, and in the Lone Star State, until his death in 1960.

6. Barber-Mizell Feud

Family feuds involving charges of cattle theft weren’t limited to the Old West. In 1870, a violent battle broke out in Florida between the Barbers and Mizells after David Mizell was fatally shot on the Osceola County land of cattleman Moses Barber, who had ordered the other man to stay off his property. By the start of the U.S. Civil War, when Florida was the Confederate army’s main purveyor of beef, Barber’s family owned one of the state’s biggest cattle operations, according to the Florida Historical Society. Following the war, Barber, who opposed the Reconstruction government, wouldn’t pay his taxes, so Mizell, the local sheriff, whose family also were ranchers, confiscated some of his cattle as compensation. Afterward, Barber announced the sheriff would be gunned down if he set foot on Barber’s land again—which was what happened in 1870 when Mizell ventured onto Barber’s property in an attempt to collect a debt for another rancher. Mizell’s death launched a spate of revenge killings and years of bad blood between the two families.