After a victorious, but later abandoned campaign in Mato Grosso, the troops of Paraguayan president and field marshal Francisco Solano López were intending to reach Uruguay through the Entre Ríos province of Argentina.

While president Mitre was secretly giving military support to the coup in Uruguay and allowing the Imperial Brazilian Navy and troops to pass through Argentine territory, he denied access to the Paraguayan Army, this led to the declaration of war from Paraguay to Argentina and the later Corrientes campaign.

General Conesa, leader of the advanced allied forces, tried to chase the fleeing soldiers, but the attempt was very risky and allowed the Paraguayans to have good counter-attacking possibilities.

[1]: 47 General Conesa, with a very intrepid action, almost ambushed with full surprise a battalion led by lieutenant Celestino Prieto, with 250 men.

After this, general Resquin ordered commander Diaz, Viveros and Prieto to place their troops in strategic positions around the swamps for ambushing and launch counterattacks on the allied armies.