Key Facts
- Duration
- 6 years (1864–1870)
- Estimated total casualties
- ~500,000
- Guerrilla phase length
- 14 months
- Occupation ended
- 1876 (Argentine and Brazilian troops)
- Belligerents
- Paraguay vs. Argentina, Brazil, and Uruguay
Strategic Narrative Overview
Paraguay initially launched offensives into Brazilian and Argentine territory, but the Alliance gradually pushed Paraguayan forces back. After decisive defeats in conventional battles, López shifted to a prolonged guerrilla campaign in Paraguay's interior. This strategy extended the war by over a year but resulted in catastrophic losses among both Paraguayan soldiers and civilians, who perished through combat, famine, and disease on a massive scale.
01 / The Origins
The war originated from regional tensions inflamed by the Uruguayan War of 1864, in which Brazil intervened against Paraguay's ally Uruguay. Paraguayan president Francisco Solano López responded by attacking Brazilian territory and crossing Argentine soil without permission, drawing both Argentina and Uruguay into an alliance with Brazil. By 1865 the Triple Alliance of Argentina, the Empire of Brazil, and Uruguay was formally united against Paraguay.
03 / The Outcome
The war ended on 1 March 1870 when President Francisco Solano López was killed by Brazilian forces at the Battle of Cerro Corá. Paraguay was compelled to cede disputed territories to Argentina and Brazil. Argentine and Brazilian troops occupied the country until 1876. Paraguay's population had been devastated, with estimates of loss disputed but widely regarded as among the most severe suffered by any nation in modern warfare.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Francisco Solano López.
Side B
3 belligerents
Kinetic Engagement Axis
Scroll horizontally to view full axis. Events plotted relatively.