Female rulers

• Merneith (Africa, 13th century BCE)
• Hatshepsut (Africa, 1508-1458 BCE)
• Artemisia I of Caria (Asia, 5th century BCE)
• Olympias (Europe, 375-316 BCE)
• Cleopatra Thea (Africa, 164-121 BCE)
• Cleopatra VII (Africa, 69-30 BCE)
• Boudica (Europe, 20-60 CE)
• Zenobia (West Asia, 240-275 CE)
• Empress Suiko (East Asia, 554-628 CE)
• Empress Wu Zetian (East Asia, 625-705 CE)
• Irene of Athens (West Asia, 752-803 CE)
• Theophano (West Asia, 943-969 CE)
• Theophano (Europe, 956-991 CE)
• Margaret of Austria (Europe, 1480-1530 CE)
• Catherine of Austria (Europe, 1507-1578 CE)
• Mary I (Europe, 1516-1558 CE)
• Elizabeth I (Europe, 1533-1603 CE)
• Joan of Austria (Europe, 1535-1573 CE)
• Mary Queen of Scots (Europe, 1542-1587 CE)
• Catherine the Great (Europe, 1729-1796 CE)

Societies from the Americas are lacking from the list above due to lack of historical records. It is likely that ancient societies in the Americas had similar proportions of female rulers. Female rulers, while a minority, were common around the world.

Conflict

Consistent with the literature on stereotypes, we find that increases in women’s legislative representation decreases conflict behavior and defense spending, while the presence of women executives increases both.

...we find that polities ruled by queens were 27% more likely to participate in inter-state conflicts, compared to polities ruled by kings.