Isabella I

Marries Ferdinand of Aragon in secret without her brother's permission. She's 18. The marriage unites Castile and Aragon and creates the foundation of modern Spain. The Pope initially refuses to sanction it. A forged papal bull is used instead.

Establishes the Spanish Inquisition with Ferdinand. Tomas de Torquemada becomes Grand Inquisitor. Over the next 350 years, the Inquisition will try over 150,000 people. Between 3,000 and 5,000 are executed.

Granada falls after a ten-year campaign. The last Muslim stronghold on the Iberian Peninsula surrenders. Eight months later, she funds Columbus's voyage west. Same year, she expels all Jews who won't convert. Three acts that reshape the world.

Dies in Medina del Campo at 53. Her will frees her Native American slaves and asks that indigenous peoples be treated justly. The request is ignored. She's buried in Granada's Royal Chapel beside Ferdinand.