Intending to subjugate the Querandí, Mendoza organizes…
June 1536 CE
Intending to subjugate the Querandí, Mendoza organizes a military expedition led by his brother, Diego de Mendoza, which is defeated on the banks of the Luján River on June 15, 1536.
Several hundred Querandí are killed by the Spanish raiders, but Diego is slain as well, along with many of of his men and several horses The Spanish cavalry is neutralized by the Querandí bolas and the remainder of the force manages to avoid being wiped out and retreats to Buenos Aires in the night.
According to Ulrich Schmidl, a soldier in the battle, about forty Spaniards and a thousand Indians were killed in the fight.
From this time forward, Buenos Aires will be at the mercy of hunger and the sporadic Querandí raids.