Cisplatine War
1825–1828
The Banda Oriental, the land east of the Uruguay River, had been annexed by Brazil as its Cisplatine Province. When its people rose in 1825 and declared for union with the United Provinces of the Río de la Plata, Brazil went to war and blockaded Buenos Aires with a large fleet. Against it the Irish-born Admiral William Brown had a few brigs and schooners and a fleet of gunboats, and used the shallow, treacherous waters of the river so well that he beat off attack after attack, cut up the Brazilian river squadron at Juncal, and kept the blockade from strangling the city completely, though he lost his best ships at Quilmes and Monte Santiago. Britain brokered a peace in 1828 that made the province independent as Uruguay.
How the fleets moved
Click a route to see which ships made it, or a battle for its summary. Routes are approximate.
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Argentine movement
Brazilian movement
Battle (size: ships engaged)
Routes are approximate.
Battles
In date order.
11 June 1826
Battle of Los PozosLos Pozos anchorage, off Buenos Aires
United Provinces success; the Brazilian attack beaten off
1
vs
0
29–30 July 1826
Battle of QuilmesOff Quilmes, Río de la Plata
Brazilian victory; 25 de Mayo wrecked
4 (1 lost)
vs
15
8–9 February 1827
Battle of JuncalJuncal Island, Uruguay River
United Provinces victory; the Brazilian river squadron destroyed
15
vs
1 (15 lost)
7–8 April 1827
Battle of Monte SantiagoOff Ensenada, Río de la Plata
Brazilian victory; the best Argentine ships lost
4 (2 lost)
vs
1
Fleets
Each navy's ships in the war, from its biggest down.