Banu Qurayza after his victory over the Meccans in the Battle of Badr, Banu Qaynuqa threatened Muhammad's political position and assaulted a Muslim woman which led to their expulsion from Medina for breaking the peace treaty of Constitution of Medina. The Qurayza remained passive during the whole Qaynuqa affair, apparently because the Qaynuqa were historically allied with the Khazraj, while the Qurayza were the allies of the Aws. Soon afterwards, Muhammad came into conflict with the Banu Nadir. He had one of the Banu Nadir's chiefs, the poet Ka'b ibn al-Ashraf, assassinated and after the Battle of Uhud accused the tribe of
Army of the North victory. The battle was favorable to Balcarce even though he again had numerical inferiority (800 royalist against 600 rebels, and in Cotagaita 2,000 royalists against 1,100 rebels). Balcarce earned the rank of brigadier, and the confidence to advance towards the Desaguadero River, border of the viceroyalty in colonial times. Due to internal disagreements Castelli had to dismiss Güemes and his gaucho soldiers. The royalist defenses were left in charge of general José Manuel de Goyeneche, who met with Castelli and signed an armistice to last for forty days from 16 May. The army moved from the encampment at La Laja,