Hernán Cortés

March 14, 1519 · 800 total casualties

Centla established the tactical pattern of the entire conquest: firearms and steel to hold, cavalry to shatter, and the terror of the unfamiliar to do the rest. In the settlement that followed, the defeated Maya presented Cortés with twenty women — among them the woman baptised Marina, La Malinche, who would become his interpreter and the indispensable voice of the conquest.

April 22, 1519 · 0 total casualties

This was the conquest's founding act of insubordination and commitment in one. By destroying his fleet Cortés bound roughly 500 men to victory or death, and by courting the Totonacs he discovered the strategy that would decide everything: the Aztec empire was an empire of resentful subjects, and those subjects could be turned.

September 1519 · 5,000 total casualties

The most important reversal of the conquest. Tlaxcala's alliance gave Cortés a secure base, a supply of provisions, and above all an army: Tlaxcalan warriors would outnumber the Spanish by ten or twenty to one in every battle that followed. Tenochtitlan did not fall to 900 Spaniards — it fell to a coalition of the Aztecs' enemies with 900 Spaniards at its head.

October 1519 · 4,000 total casualties

Cholula was calculated terror, and it worked: news of it ran ahead of the Spanish column all the way to Tenochtitlan and no city offered them battle again on the road. It also became the conquest's most contested episode — Cortés claimed a pre-emptive strike against a genuine plot; indigenous accounts and Bartolomé de las Casas called it butchery of the defenceless.

November 8, 1519 · 0 total casualties

For months the most powerful state in the Americas was governed by a hostage. Why Moctezuma admitted the Spanish at all remains debated — the old story of a god-king paralysed by prophecy is largely a post-conquest invention, and the likelier explanation is a ruler taking the measure of a small, strange embassy he expected to control.

May 28, 1520 · 20 total casualties

A Spanish civil war fought on Mexican soil that doubled Cortés's strength — and cost him the capital. Narváez's men carried smallpox ashore with them, unleashing the epidemic that would kill more Aztecs than every battle of the war combined. In Cortés's absence, Alvarado massacred the Aztec nobility and destroyed the fragile peace.

June 30, 1520 · 6,000 total casualties

The worst defeat any conquistador force ever suffered, and the moment the conquest nearly ended. Cortés lost his artillery, his horses, his plunder, and most of his men. That he survived at all — and returned a year later to take the city — is why the night is remembered by the name the Spanish gave it while weeping under a tree at Tacuba.

July 7, 1520 · 3,000 total casualties

Otumba saved the conquest. A broken force with no firepower left should have been annihilated; instead a single decapitating charge exploited the Aztec practice of directing battle from a visible standard. The road to Tlaxcala stayed open, and Cortés reached his allies alive — with a year to build the army and the fleet that would return.

May 26 – August 13, 1521 · 150,000 total casualties

The end of the Aztec empire and one of the deadliest sieges in human history — perhaps 100,000 or more died of hunger, disease, and fighting. Tenochtitlan, one of the largest cities on earth, was systematically destroyed and Mexico City built on its rubble. The Spanish won the siege at the head of an indigenous army; the war that ended the Aztec empire was fought largely by other Mexicans.