Treaty of Córdoba (1821): End of Spanish Rule and Birth of the Mexican Empire

The Treaty of Córdoba, signed on August 24, 1821, in Córdoba, Veracruz, formally ended the Mexican War of Independence (1810–1821) and recognized Mexico as a sovereign and independent nation, free from Spanish colonial rule after over 300 years. The treaty ratified and expanded upon the Plan of Iguala (proclaimed February 24, 1821), which had united conservative royalists, moderate insurgents, and the Catholic Church under the "Three Guarantees": religion (Catholicism as the official faith), independence, and union (equality between peninsulares and criollos).^[a][b]

It marked the culmination of a dramatic shift: former royalist officer Agustín de Iturbide allied with insurgent leader Vicente Guerrero in early 1821, forming the Army of the Three Guarantees, which rapidly gained control of most of New Spain. By mid-1821, royalist forces held only Mexico City and Veracruz.^[a][c]

Key Details and Signers

The treaty was negotiated and signed by:

• Agustín de Iturbide (1783–1824), commander of the Army of the Three Guarantees and de facto leader of the independence movement in its final phase.^[a]
• Juan O'Donojú (1762–1821), the newly arrived Spanish Jefe Político Superior (Superior Political Chief) and acting viceroy/captain-general of New Spain. O'Donojú, a liberal who had suffered under Ferdinand VII's absolutist repression, recognized the inevitability of independence and signed to avoid further bloodshed.^[a][d]

The document consisted of 17 articles affirming Mexican sovereignty, establishing a provisional regency, and outlining the transition to monarchical rule.^[a]

Main Terms

• Mexico was declared a "sovereign and independent" nation, to be known as the Mexican Empire, organized as a constitutional monarchy.^[a]
• The throne was to be offered first to King Ferdinand VII of Spain; if he declined, then to his brothers (Infantes Carlos, Francisco de Paula, or Carlos Luis), or another European prince acceptable to the Mexican Cortes (Congress).^[a]
• If no European prince accepted within a set period, the Mexican Cortes could elect a new monarch (a provision that ultimately enabled Iturbide's self-proclamation as emperor).^[a]
• The Catholic Church retained its privileged status, property, and fueros (privileges); equality between Europeans and American-born Spaniards was guaranteed; and a provisional junta and regency would govern until a congress convened.^[a][b]
• Spanish troops were to withdraw peacefully, and existing laws and officials were to remain in place during the transition.^[a]

Impact on Texas

By transferring sovereignty from the Spanish Crown to the new Mexican government, the treaty brought Texas (then the province of Tejas within the Provincias Internas) under Mexican authority. The boundaries established by the Adams-Onís Treaty (1819–1821) remained intact, with Texas west of the Sabine River as Mexican territory.^[e]

This shift enabled the legalization and expansion of the empresario system, a colonization policy inherited from late Spanish reforms but actively implemented by Mexico to populate its northern frontier. Empresarios (land agents) received large grants in exchange for recruiting Catholic families (primarily from the United States and Europe) to settle, farm, and defend the region.^[f][g]

Stephen F. Austin became the most prominent empresario: His father, Moses Austin, had secured a Spanish grant in 1821 just before independence, which Stephen renegotiated and expanded under Mexican law. Beginning in late 1821, Austin brought in the "Old Three Hundred" families, establishing Anglo-American colonies along the Brazos and Colorado Rivers. Between 1821 and 1835, Mexico issued over 40 empresario contracts, leading to rapid population growth in Texas—from a few thousand Tejanos and Native groups to tens of thousands of Anglo settlers—setting the demographic and cultural stage for future tensions and the Texas Revolution (1835–1836).^[f][g]

Aftermath and Legacy

The Army of the Three Guarantees entered Mexico City triumphantly on September 27, 1821, and the Declaration of Independence of the Mexican Empire was proclaimed the next day. A provisional regency was installed, with Iturbide as its head.^[a][c]

Spain's government in Madrid rejected the treaty, claiming O'Donojú lacked authority to cede the colony, and refused to recognize Mexican independence until the Santa María–Calatrava Treaty in 1836 (after the loss of most colonies). Despite this, the treaty was effective de facto: Spanish forces evacuated, and Mexico began functioning as an independent state.^[a][h]

Iturbide, unable to secure a European monarch and amid political instability, had himself proclaimed Emperor Agustín I in 1822—a short-lived monarchy that collapsed in 1823, leading to the establishment of the First Mexican Republic. The treaty's monarchical framework thus quickly gave way to republicanism, but it successfully ended colonial rule and initiated Mexico's independent era.^[a][b]

For Texas, the treaty's most enduring consequence was the transition to Mexican rule and the empresario-driven Anglo colonization, which transformed the region demographically and politically, contributing directly to the conflicts that culminated in Texas independence in 1836.^[f]