Mexico’s vertical tricolour of green, white, and red centres the national coat of arms—an eagle devouring a serpent on a nopal cactus—within the white band. Rooted in the 1821 independence tricolour, the emblem was standardised in 1916 and the current layout fixed in 1968. Colours are now read as hope (green), unity (white), and the blood of national heroes (red). Strict law (Ley sobre el Escudo, la Bandera y el Himno Nacional) defines design, proportions (4:7 in official use), protocols, and dignified treatment.
Mexico’s flag descends from the 1821 tricolour of the Army of the Three Guarantees that heralded independence from Spain. Early republic banners used green, white, and red with varied central emblems. In 1823, an eagle perched on a prickly pear cactus devouring a serpent—drawn from Mexica lore about Tenochtitlan’s founding—was adopted for the coat of arms and subsequently refined.
In 1916 a presidential decree established a forward‑facing eagle rendering; the modern graphic canon was regularised in the twentieth century. Ahead of the 1968 Olympic Games, the state fixed current flag specifications, ensuring a codified emblem and consistent manufacture.
Symbolism
has evolved: once read as independence (green), religion (white), and union (red), the colours are now commonly interpreted as hope, unity, and the blood of patriots. The coat of arms synthesises pre‑Hispanic myth, national resilience, and continuity of state.
The Ley sobre el Escudo, la Bandera y el Himno Nacional prescribes proportions, colour references, emblem geometry, protocols for state ceremonies, half‑masting, and respectful retirement. Civil flags may omit the arms; state, military, and official versions display the device.
Flag Day (Día de la Bandera) on 24 February anchors public ritual. Educational and civic ceremonies emphasise correct salutes and handling. Misuse is sanctioned; commercial appropriation requires permission.
While artistic refinements to the arms have occurred, the tricolour framework remains stable. The flag’s presence in plazas, schools, border ports, and foreign missions maintains its role as a unifying national symbol connecting ancient legend to contemporary republican identity.