13 Historical Rulers Who Executed Members Of Their Own Families

Royal Title: Queen of England

Relatives Killed:

Her royal arch-rival, Mary, Queen of Scots. Always a Catholic rival to Elizabeth, Mary thought of herself as the rightful queen of England. She was raised in France but came back home to Scotland in her teens. Mary married her own first cousin, had an heir, and got into a lot of political trouble (her alleged lover and third husband might have killed her second spouse). Mary wound up in battle against her own nobility, abdicated her throne, and threw herself on the mercy of her cousin Elizabeth by fleeing to England. Mary was imprisoned by her for decades until a plot to kill Elizabeth that allegedly implicated Mary was revealed. The Queen of Scots was executed in 1587.

Her second cousin, Thomas, Duke of Norfolk. One of the Queen of Scots's followers was Elizabeth's own cousin, an English duke named Thomas Howard. He became involved in multiple insurrections against Elizabeth, leading to his execution in 1572. 

Elizabeth's first-cousin-twice-removed, Robert, Earl of Essex. One of the Virgin Queen's favorites was Robert Devereux, son of her first-cousin-once-removed, Lettice Knollys. He charmed the much older Elizabeth but offended her many times and may have even possibly tried to overthrow the government. Elizabeth ultimately had him beheaded at the Tower of London in 1601.

Royal Title: King of Judea

Relatives Killed:

His wife, Mariamne. Herod wasn't born a Judean; he was the Roman pick to rule the province of Judea. He married into the Judean royal family - in this case, by wedding a princess named Mariamne. This union was supposed to lead to peace, but it didn't really have that effect. Herod was intensely possessive of Mariamne and, after accusing her of adultery, executed her in 29 BCE, along with Mariamne's mother.

His surviving sons by Mariamne, Alexander and Aristobulus. These two boys arguably had a better claim to the throne than Herod. Herod and his eldest son by another wife, Antipater II, heard that these two princes wanted Herod dead to get vengeance for their mother. Antipater continually poured poison in Herod's ears, so much so that he had the boys strangled in 7 BCE.

Royal Title: Pharaoh of Egypt

Relatives Killed: 

Her sister Arsinoe IV. Cleopatra's little sister wanted to be pharaoh herself and even rallied an army in support of her claim, but Cleopatra and her Roman allies defeated her. Arsinoe was exiled to Turkey and later murdered on her sister's orders.

Her two brothers (also her husbands), Ptolemy XIII and Ptolemy XIV. In true royal Egyptian fashion, Cleopatra married both her brothers, but they died under suspicious circumstances. Ptolemy XIII set himself up as Cleopatra's rival in Alexandria but died in battle with her Roman allies, led by Caesar. Next up was Ptolemy XIV, who was possibly killed by Cleopatra so that her son by Caesar, Caesarion, could assume power.

Royal Title: King of England

Relatives Killed: 

Any royal rivals, including his first cousin once removed, Edward Stafford, Duke of Buckingham. One of the most important nobles in the kingdom and of royal descent several times over, Stafford may have had monarchical ambitions, but Henry nipped that in the bud by executing the duke for treason in 1521.

His brother-in-law (husband of his sister Margaret), James IV of Scotland. The two monarchs were allied for some time until war broke out and Henry's forces defeated - and killed - James at the Battle of Flodden in 1513.

Henry also bumped off many other royal cousins who posed a threat to his throne, including Edmund de la Pole in 1513.

Longtime family friend and cousin Margaret Pole, who was hacked to death at an old age. 

Two of Henry's wives, Anne Boleyn and Catherine Howard, who were his eighth cousins. Both were beheaded after being charged with adultery.

Royal Title: Empress of Rome

Relatives Killed: 

Allegedly, her uncle and husband Claudius. Agrippina was his fourth wife, and she started jockeying for power soon after their marriage. She started pushing her own son, Nero, to be Claudius's heir, rather than his own son Britannicus; Claudius adopted little Nero and betrothed him to his own daughter.

In 54 CE, Claudius died following a big feast. Rumor had it that Agrippina convinced Claudius's eunuch, who tasted all the imperial food before his master, to poison Claudius's mushroom dish. Other versions of the tale have Agrippina more directly poisoning her husband.

Royal Title: Duke of Burgundy

Relative Killed: His cousin, Louis, Duke of Orleans. When Charles VI, King of France, went mad, his little brother, Louis, took a great deal of power into his own hands. So did the dukes of Anjou, Berry, and Burgundy, but it was Burgundy - Duke John the Fearless - who emerged as the number-one rival to Orleans.

Orleans and Burgundy began a tug-of-war over control of France. Orleans even went so far as to allegedly seduce his sister-in-law, Queen Isabeau. Burgundy in turn kidnapped the heir to the French throne, and it's believed Orleans may have then tried to assault Burgundy's wife. This didn't end well - Burgundy hired a gang of assassins to murder his cousin Orleans on the streets of Paris. They ultimately beat the dead duke to a pulp. Burgundy later claimed he did it because Orleans was trying to kill his brother, the king, by using black magic.