Tuyutí

FactsBattle fact sheet

Move 1The board: a camp backed against the swamp

On 11 June 1865, at Riachuelo, the Brazilian squadron took from Paraguay the ability to contest the river. In April 1866 the Allies crossed the Paraná at Paso de Patria and entered Paraguayan territory. On 2 May López attacked Venancio Flores's vanguard at the Estero Bellaco and was repulsed. On 20 May the Allies encamped at Tuyutí; that same day López moved his headquarters to Paso Pucú, a few kilometers to the north.

Tuyutí was dry high ground between swamps. To the south lay the Estero Bellaco; to the west, the Potrero Piris and the Laguna Piris; to the north, the Estero Rojas and the Paraguayan trenches. George Thompson, the English engineer who built those trenches for López, described the esteros like someone who had measured them: 1 to 2 meters of water over deep mud, reeds taller than a man and so dense they were almost impassable. One could only get through at the fords, where the reeds had been pulled out, and even there with water up to the waist. All around, brush of thorns and creepers where one could barely see twenty meters.

The swamp protected the Allies and, at the same time, hemmed them in. But it also decided where an attacker could come out: through a few fords and trails, known or still to be cut. That is the board on which López chose to play.

Move 2The plan: attack before being attacked

Until 23 May, according to Thompson, the Paraguayan plan was to wait. When the Allies attacked the trenches at Paso Gómez, 10,000 men would come out of the Potrero Sauce along a road already cut through the brush — only a few meters remained to break through — and fall on the Allied rear. López changed his mind on 23 May. A year later, he explained to Thompson that he had learned of Bartolomé Mitre's plan to attack on the 25th, did not like it and decided to prevent it by attacking first.

The new plan was a frontal attack with a double envelopment. Colonels José Eduvigis Díaz and Hilario Marcó would attack the center, coming out of the brush unseen. General Francisco Isidoro Resquín, formed up before dawn behind the palm groves of Yataity Corá, would attack the Allied right, where the Argentines were. General Vicente Barrios would march along the edge of the swamp to the Potrero Piris and form up there, in the rear of the Allied left, where the Brazilians were. The cavalry of Barrios and of Resquín were to meet behind the camp. It was an encirclement.

Everything depended on simultaneity, and simultaneity depended on Barrios, who had the longest route. That is why the signal for the general attack would only be given when he was ready: a cannon shot from Paso Gómez, in Thompson's version; a rocket, in others. Barrios's route was a trail cut under the brush, along the edge of the swamp, where the men passed one by one and the horsemen dismounted, leading their horses.

Move 3The clock: the signal comes close to noon

Thompson, who spent that day at López's side, wrote that Barrios was expected at the other end of the defile at 9:00. He only got through at 11:30, and only then was the signal given. Brazilian military historiography records 11:55; Osório, in the combat report he sent to Mitre on 26 May, says the attack came "from 11 to 12 in the morning" (our translation); the contemporary sketch by Major Conrado Bitancourt starts the positions at 11:15. The versions differ on the minute and agree on the essential: the attack that was supposed to come in the morning went in close to noon.

And it found the opponent formed up. "Fortunately for the Allies," Thompson wrote, "they happened to be all under arms": Mitre was going to carry out a reconnaissance in force against the Paraguayan lines that day. The surprise had two conditions — arrive unseen and arrive before the opponent formed up. The first worked in part: Díaz and Resquín came out of the brush and the palm groves without being noticed. The second stayed behind on Barrios's trail.

Three minutes after the signal, according to Thompson, the fighting was general along the whole line, and the rifle fire was one continuous sound, broken by the Allied guns.

Move 4The center and the artillery

In the center, Díaz attacked Flores's vanguard. To reach it, his men had to cross a deep swamp, under fire from the Allied artillery and rifles from the moment they left the brush; Thompson wrote that the swamp was literally filled with dead. Even so the attack opened a breach where the Uruguayans stood. Brigadier Antônio de Sampaio counterattacked with the 3rd Division and held through hours of back-and-forth — Thompson says that Brazilians and Paraguayans pushed each other back three times between the Bellaco and the brush. Sampaio was wounded three times, on his 56th birthday, and died on 6 July. Osório plugged the breach with Argolo's 1st Division and a brigade of Guilherme's 4th, and the 6th Division closed the gap between Flores and the artillery.

The artillery is at the center of the explanation. In front of the vanguard stood Lieutenant Colonel Emílio Mallet's 1st Horse Artillery Regiment. According to Brazilian military historiography, Mallet had a wide, deep ditch dug in front of the guns, with the earth spread out so as not to give away the obstacle, and the charges of the Paraguayan cavalry stopped at it, under canister. The sources differ on the number of guns — 24, 28 or 30 — and the phrase the Army's tradition attributes to Mallet, "they shall not pass through here" (our translation), appears in three wordings and without any contemporary document. The record from the other side is more general and harsher: Thompson wrote that the Allies had all their artillery in action, almost all of it rifled, while the Paraguayan artillery stood idle. The Paraguayans brought only four howitzers to the attack, and all four were taken.

Thompson adds the weaponry: almost no rifled musket on the Paraguayan side, most of the weapons still flintlocks, against an Allied army in which there was no small arm that was not rifled.

Move 5The flanks: the encirclement that came late

On the Paraguayan left, Resquín's cavalry swept everything before it in the first charge: it scattered the Corrientes cavalry of Generals Cáceres and Hornos, much of which was on foot. Part of it reached the Argentine artillery, and there, without support, was destroyed by the Argentine reserve. Resquín's infantry went in afterward and was broken by the Argentine artillery and infantry. The cavalry reserve tried to go around the Allied right through the palm grove to meet Barrios and was repulsed. Only one officer, Major Olabarrieta, got through the line with some twenty men and reached the meeting point. Barrios had already been beaten. He fought his way back, almost alone and wounded.

On the Paraguayan right, Barrios finally emerged into the Potrero Piris, in the rear of the Brazilian left. He ran into the light brigade of General Antônio de Souza Netto, and Osório sent there Mena Barreto's 2nd Cavalry Division, with infantry and artillery. The plan of the camp drawn by the engineer André Rebouças in June 1866 shows the Brazilian cavalry fighting on foot in the Potrero Pires. Osório wrote that he personally directed that last fight, and that the Paraguayan remnants only escaped through three trails cut in the brush.

The title of Bitancourt's sketch sums up what went wrong with the plan: the positions from 11:15 to 3 in the afternoon, and "from those hours to 4 1/2", when the enemy, "making its way through the woods, attacked the left flank with all its forces" (our translation). The flank blow, which was supposed to close the encirclement at the start, came last, after the center and the Paraguayan left had already broken.

Move 6The price and the aftermath

At 16:00, according to Thompson, or at 16:30, according to Osório, it was over. Thompson counts 6,000 Paraguayans dead on the field and 7,000 wounded taken to the Paraguayan hospitals; the standard count stays at the same 13,000, more than half of those who attacked. Osório, two days later, recorded more than 3,000 enemy dead on the field and 2,200 already buried. There were almost no unwounded prisoners: about 350, all wounded, for Thompson; 180, in Osório's report. On the Allied side, the official count gives 996 dead and nearly 4,000 casualties; Thompson and the encyclopedia entry by the historian Thomas Whigham speak of about 8,000.

López did not see the battle. Thompson, who was with him, says he stayed in a wood from which he could see the smoke and nothing else, and that at night he had the bands play so that his own camp would believe in a victory. He only learned the size of the loss the next day. The 10,000 men who had been neither killed nor wounded took days to be gathered up.

The Allies did not pursue: they had no horses. They stayed in the camp, which they entrenched, until September. Thompson thought that, after 24 May, they could have gone around the Paraguayan left almost without losses and reached Humaitá from the rear; instead, he wrote, they were paralyzed. Paraguay never again assembled a force of that size, and the war became a war of trenches, with the fortress of Humaitá closing the river.

VerdictWhy it ended the way it did

MythsWhat is told and what the record shows

• What is told

  The attack was set for dawn and was five hours late.

  What the record shows

  George Thompson, who was in the Paraguayan camp, wrote that Barrios was expected at 9:00 and that the signal came at 11:30; Brazilian military historiography gives 11:55 and Osório, "from 11 to 12" (our translation). The delay is certain. Its size depends on which planned time one accepts.

• What is told

  Mallet's ditch won the battle — "they shall not pass through here" (our translation).

  What the record shows

  The ditch in front of the 1st Horse Artillery Regiment comes from Brazilian military historiography and is consistent with the result, but the number of guns varies (24, 28 or 30) and the phrase appears in three wordings, without any contemporary document: it is Army tradition. The witness on the Paraguayan side does not mention a ditch and explains the defeat by the Allied artillery, the swamp and the weaponry.

• What is told

  The Paraguayans attacked drunk on cane liquor mixed with gunpowder.

  What the record shows

  It was an Allied accusation of the time. Thompson denies it: the Paraguayan soldiers went into combat on an empty stomach. The looting of food and drink that is told about belongs to another battle, the second at Tuyutí, on 3 November 1867.

• What is told

  There were two Allies for every Paraguayan.

  What the record shows

  The phrase is Thompson's. The sources give about 24,000 Paraguayans against 32,000 to 35,000 Allies: Allied superiority, but not two to one.

QuestionsFrequently asked questions

SourcesSources

1. George Thompson, The War in Paraguay, London, Longmans, Green & Co., 1869, ch. XI. — archive.org
2. Manuel Luís Osório, combat report to Bartolomé Mitre, Tuiuti, 26 May 1866, transcribed in Cláudio Moreira Bento, A Batalha de Tuiuti, a maior batalha campal da América do Sul (AHIMTB). — ahimtb.org.br
3. André Rebouças and Bernardino de Sena Madureira, Plan of the camp and of the Battle of Tuyuty on 24 May 1866 (National Library of Brazil). — commons.wikimedia.org
4. Conrado Maria da Silva Bitancourt, Esboço da batalha de Tuyuty (National Library of Brazil). — commons.wikimedia.org
5. Thomas L. Whigham, "Tuyutí, Battle of", Encyclopedia of Latin American History and Culture. — encyclopedia.com
6. Carlos Mário de Souza Santos Rosa, "Tuiuti, 160 anos", EBlog of the Brazilian Army, 2026. — eblog.eb.mil.br
7. Battle of Tuyutí — English Wikipedia. — en.wikipedia.org
8. Batalha de Tuiuti — Portuguese Wikipedia. — pt.wikipedia.org
9. Batalla de Tuyutí — Spanish Wikipedia. — es.wikipedia.org

Images

• Fig. 01 — Plan of the camp and of the battle of Tuyutí drawn by the engineers André Rebouças and Bernardino de Sena Madureira, dated from the camp on 10 June 1866. The arrows mark the Paraguayan columns; on the left, the Potrero Pires, where Barrios's column arrived.: André Rebouças and Bernardino de Sena Madureira · Lit. Mège y Willems, Montevideo · National Library of Brazil · Public domain
• Fig. 02 — Painting by Cándido López, an Argentine officer in the war, made years later from his campaign sketches: an episode of the 2nd Buenos Aires Division at the battle of Tuyutí, 24 May 1866. Museo Histórico Nacional, Buenos Aires.: Cándido López · Museo Histórico Nacional (Argentina) · Public domain
• Fig. 03 — Sketch of the battle of Tuyutí by Major Conrado Maria da Silva Bitancourt, commander of the vanguard's engineers: the positions from 11:15 to 15:00, and from then to 16:30, when the attack through the brush fell on the Brazilian left flank.: Conrado Maria da Silva Bitancourt · Imperial Instituto Artístico, Rio de Janeiro · National Library of Brazil · Public domain
• Fig. 04 — The Tuyutí battlefield in the French magazine L'Illustration of 1 September 1866, engraved from sketches by two officers of the Brazilian army. The engraving marks the ditch in front of the Paraguayan camp and the columns that came down against the Allied line.: L. Kautz, engraver, after sketches by Floriano Bravos and Lobos · L'Illustration, vol. XLVIII, no. 1,227 · Public domain
• Fig. 05 — The Paraguayan attack on the Argentine lines at Tuyutí, in an illustration by Francisco Fortuny made in 1893 for the Álbum de la Guerra del Paraguay, published in Buenos Aires.: Francisco Fortuny · Álbum de la Guerra del Paraguay (ed. José C. Soto), Buenos Aires, 1893–1896 · Public domain