When did the First Mexican Empire exist?

The First Mexican Empire existed 1821–1823. On this map it is drawn 1822–1823.

How large was the First Mexican Empire?

At its greatest extent drawn on this map, the First Mexican Empire covered about 3.6 million km². That is the largest area the border data gives it across the years it is drawn, not necessarily its greatest extent in history.

North America · Independence and the new republics

First Mexican Empire

1821–1823

See it on the map → Wikipedia ↗

Existed: 1821–1823
Shown on the map: 1822–1823
Peak area: 3.6M km²
Region: North America

Overview

The First Mexican Empire (Primer Imperio Mexicano) was the short-lived monarchy that immediately followed Mexico's independence from Spain — the first sovereign Mexican state and, at its greatest extent, one of the largest countries in the Americas, stretching from Oregon/California down through Central America to Panama (as the former Captaincy General of Guatemala joined it). Independence was achieved in 1821 when the royalist creole officer Agustín de Iturbide allied with the insurgent Vicente Guerrero under the Plan de Iguala, and the Treaty of Córdoba (24 August 1821) recognized Mexican sovereignty.

History

When the offered European (Bourbon) monarch failed to materialize, Iturbide had himself proclaimed Emperor Agustín I, crowned in July 1822. His empire was beset from the start by an empty treasury, a hostile Congress (which he dissolved), and republican opposition. The revolt began with the Plan de Casa Mata (February 1823), led by Antonio López de Santa Anna and Guadalupe Victoria, which demanded a new congress and the end of the monarchy.

Decline and legacy

Iturbide abdicated in March 1823 and went into exile; when he returned to Mexico in 1824 (unaware he had been declared an outlaw), he was arrested and executed by firing squad. The empire dissolved: the Central American provinces seceded to form the United Provinces of Central America, and Mexico itself became a federal republic in 1824 (entry 14). The First Empire is remembered as a false start, though Iturbide is honored as a consummator of independence, and its green-white-red flag with the eagle-and-serpent became the basis of Mexico's enduring national symbols.

Common questions

What was the First Mexican Empire?: The First Mexican Empire (Primer Imperio Mexicano) was the short-lived monarchy that immediately followed Mexico's independence from Spain — the first sovereign Mexican state and, at its greatest extent, one of the largest countries in the Americas, stretching from Oregon/California down through Central America to Panama (as the former Captaincy General of Guatemala joined it).
When did the First Mexican Empire exist?: The First Mexican Empire existed 1821–1823. On this map it is drawn 1822–1823.
How large was the First Mexican Empire?: At its greatest extent drawn on this map, the First Mexican Empire covered about 3.6 million km². That is the largest area the border data gives it across the years it is drawn, not necessarily its greatest extent in history.
Who ruled the First Mexican Empire?: When the offered European (Bourbon) monarch failed to materialize, Iturbide had himself proclaimed Emperor Agustín I, crowned in July 1822. His empire was beset from the start by an empty treasury, a hostile Congress (which he dissolved), and republican opposition.
How did the First Mexican Empire end?: Iturbide abdicated in March 1823 and went into exile; when he returned to Mexico in 1824 (unaware he had been declared an outlaw), he was arrested and executed by firing squad. The empire dissolved: the Central American provinces seceded to form the United Provinces of Central America, and Mexico itself became a federal republic in 1824 (entry 14).

Sources

This compendium cites its sources once for the whole document rather than per territory, and states that it was written from established reference works with targeted checks on current facts, rather than from a fresh multi-source research pass. It names the English Wikipedia article for each polity and its key figures as the basis of these profiles, supplemented by Encyclopaedia Britannica, the US National Park Service and the World History Encyclopedia. The article this entry is anchored on:

Wikipedia — First Mexican Empire en.wikipedia.org/wiki/First_Mexican_Empire

This entry was last updated 12 September 2026.

This entry was researched and drafted with AI from the sources above, and has not been reviewed by a historian. How entries are made

Text available under CC BY-SA 4.0: reuse it with a credit to The World Through Time and a link to this page. Passages drawing on the Wikipedia articles listed above are also licensed CC BY-SA 4.0 by their contributors.

Border geometry for the map itself comes from Cliopatria v0.12 (Seshat Global History Databank, CC-BY-4.0).

See the First Mexican Empire in its world

Open the atlas at 1823 and every neighbour, rival and successor is on screen with it — then drag the slider and watch what happens next.

Open the map at 1823 →