Family research · Phase 15 of the world atlas

Flags of Uruguay

The land on the eastern bank of the Uruguay River — the "Banda Oriental" — sat for more than a century on the exact seam between two American empires, and both fought for it accordingly. Portugal pushed a trading post across the water from Buenos Aires in 1680; Spain answered by founding Montevideo forty years later to hold the line; and when Spanish rule finally collapsed, Portuguese Brazil simply annexed the territory outright rather than let it go independent, precisely because whoever held the eastern bank held the mouth of the Río de la Plata.

What makes Uruguay's founding genuinely unusual in this atlas is that it did not become independent by winning its own war of liberation the way most of its neighbors did. After the 1825 Thirty-Three Orientals uprising dragged Argentina and Brazil into a war neither could win outright, Britain stepped in as mediator: the 1828 Treaty of Montevideo, guaranteed by the United Kingdom, created Uruguay as a deliberate buffer state wedged between its two much larger neighbors — independence granted less to satisfy Uruguayan self-determination than to keep Argentina and Brazil from fighting each other over the territory again.

Scope of this page: the lands of present-day Uruguay, c. 1500s (Charrúa era)–present. Part of a larger atlas — see the linked pages at the bottom.

Two rulers at once, for a century

Uruguay's own real border, traced whole, split for one specific stretch — Portugal's small Colônia do Sacramento enclave against the Spanish Banda Oriental that surrounded it. Press play, or drag the slider, to watch who held which piece, era to era.

This atlas only splits a country's internal map when two pieces were genuinely, separately governed at once. From 1680 to 1777, that's exactly what happened here: Portugal held the small trading enclave of Colônia do Sacramento, directly across the Río de la Plata from Buenos Aires, while Spain held the rest of the Banda Oriental from Montevideo outward — two different crowns administering two different pieces of the same modern country, at the same time. Outside that span, whichever crown or state held the upper hand held the whole territory, not a separate piece of it.

to 1680s

Charrúa and other indigenous peoples

Real traced border, with one schematic internal cut: the small Colônia do Sacramento enclave carved out of the southwestern coast for 1680–1777, approximate rather than surveyed.

nine white/blue stripes, Sol de Mayo in the canton — unchanged since 1830

1830 – present

Oriental Republic of Uruguay (modern)

RepublicFructuoso RiveraRoman Catholic (until 1917–19 secularization)

Migration & conquest:Immigration: Italian & Spanish immigrants (1880s–1930s)Emigration: political exiles fleeing the dictatorship (1973–85)

Who & why: the 1830 constitution formally establishes the Oriental Republic of Uruguay following the 1828 British-brokered independence settlement, fixing the flag in its final form the same year. The 20th century brings real turbulence — including a 1973–85 civil-military dictatorship — but none of it touches the flag itself, which has flown unaltered through democratic government, dictatorship, and the return to democracy alike.

What it represents: nine alternating white and blue horizontal stripes, one for each of the republic's nine original departments, with a golden Sol de Mayo (Sun of May) in a white canton — the same sun emblem carried on Argentina's flag, a direct nod to the shared revolutionary-era heritage of the Río de la Plata provinces.

Paint guide

Proportions2:3, fixed by law; shown here simplified with five representative stripes rather than all nine.

LayoutNine horizontal stripes (five white, four blue) with a white canton bearing the golden Sol de Mayo, a sun with a face and sixteen alternating rays.

White#F4EFE1

Blue#0038A8

Gold sun#F6B40E

Thirty-Three Orientals banner, light blue/white/red with "Libertad o Muerte"

1825 – 1828

Independence and the buffer-state settlement

Republic, independence declaredJuan Antonio LavallejaRoman Catholic

Who & why: the "Treinta y Tres Orientales" (Thirty-Three Orientals), led by Juan Antonio Lavalleja, land on the Banda Oriental in April 1825 and rise against Brazilian rule, triggering a war between Argentina and Brazil over the territory. Neither side can settle it by force, so Britain steps in to broker the December 1828 Treaty of Montevideo, under which both Argentina and Brazil recognize an independent Uruguay — created deliberately as a buffer state between them, a genuinely distinctive founding rationale among this atlas's republics.

What it represents: the independence fighters' own historic banner, sometimes shown as a light-blue, white, and red tricolor carrying the motto "Libertad o Muerte" (Liberty or Death) — the predecessor to the fixed 1830 national design.

Paint guide

ProportionsNo fixed ratio recorded for this irregular, campaign-era banner.

LayoutThree horizontal bands — light blue, white, red — with the motto "Libertad o Muerte" across the field.

Light blue#75AADB

White#F4EFE1

Red#9C3B28

left: Portuguese/United Kingdom colonial banner (1816–22); right: Brazilian Empire banner (1822–25)

1816 – 1825

Cisplatina (Portuguese/Brazilian rule)

Annexed provinceCarlos Frederico LecorRoman Catholic

Ruling house:House of Braganza

Who & why: Portuguese-Brazilian forces invade in 1816 and complete the annexation of the Banda Oriental by 1817, renaming it the "Cisplatine Province" and formally folding it into the United Kingdom of Portugal, Brazil and the Algarves. After Brazil's own 1822 break from Portugal, the province passes intact into the newly independent Empire of Brazil. Brazilian rule over the province is a direct trigger for the Thirty-Three Orientals' 1825 uprising.

What it represents: the province flew under Portuguese colonial authority through 1822, then under the banner of the Brazilian Empire afterward — shown here honestly as two halves of one entry rather than a single continuous flag, since the ruling banner itself changed mid-period even though the annexation did not.

Paint guide

ProportionsNo fixed ratio recorded for the province's own use; shown as an illustrative split panel.

LayoutLeft half: Portuguese colonial blue field. Right half: Brazilian Empire green field. Center: simplified gold armillary/imperial emblem.

Portuguese blue#204B5C

Brazilian green#2A7F3E

Gold emblem#F6B40E

Cross of Burgundy on white — standard Spanish colonial banner

1680s – 1816

Banda Oriental (Spanish colonial, contested with Portugal)

Colony, contestedManuel LoboRoman Catholic

Migration & conquest:Immigration: Canary Islander settler families (1726–29)

Ruling house:House of Habsburg (Spain)House of Bourbon (Spain)House of Braganza (Portugal)

Who & why: Spain and Portugal dispute this stretch of the eastern riverbank for well over a century. Portugal opens the contest by founding Colônia do Sacramento in 1680, directly across the river from Buenos Aires; Spain answers by founding Montevideo in 1724–30 to secure the eastern bank against further Portuguese encroachment. The territory remains a genuine, long-running frontier flashpoint between the two empires' American claims until Portuguese/Brazilian forces finally seize it outright in 1816.

What it represents: the Cross of Burgundy — a red saltire on a white or cream field — the standard military and civil banner flown across Spain's American colonies, including the contested Banda Oriental garrisons and Montevideo itself.

Paint guide

ProportionsNo fixed ratio recorded for colonial-era use.

LayoutWhite/cream field, red saltire (Cross of Burgundy); shown here with straight bands rather than the historically jagged, knotted-branch edges.

White#F4EFE1

Red saltire#9C3B28

placeholder field — pre-contact era, no flag survives

to 1680s

Charrúa and other indigenous peoples

No unified polityNo single ruler documentedCharrúa spiritual tradition (poorly documented)

Who & why: the Charrúa and other indigenous peoples inhabit the territory in small, mobile communities before European contact, with no single ruling authority over the region. Comparatively sparse Spanish and Portuguese settlement follows contact, a direct consequence of the territory's position as a frontier zone between the two empires rather than a core holding of either.

What it represents: no flag or fixed territorial banner is documented for this era or these peoples. Shown here honestly blank rather than invented.

Paint guide

ProportionsN/A — no attested flag.

Reading the tags

No unified polity — no single ruling authority

Colony, contested — disputed frontier between two empires

Annexed province — absorbed outright into a larger state

Republic, independence declared — sovereignty claimed, not yet settled

Republic — sovereign, internationally recognized

Leader — the named ruler most associated with the era's start

State religion — the official/established faith, not the population's

Find the records

Family history research for Uruguay lives in a different project, Record Atlas, which maps which archive actually holds the paper for a given place and era.

Search Record Atlas for Uruguay →

More of the atlas

This page is one lineage in a larger set. See the region-wide map and the other countries here:

Flags Atlas indexSearch every country and hub South America hubThe continent's countries, side by side