San Martin landed in Pisco, on September 8, 1820. De la Serna, through secret negotiations, was named commander-in-chief of the army gathered at Aznapuquio to protect the capital against San Martin's advance. He was ordered by the viceroy to march to Chancay.
On September 8, 1820, San Martin landed in Pisco. De la Serna, through secret agreements, was appointed commander-in-chief of the army assembled at Aznapuquio to protect the capital from San Martin's advance. He was ordered by the viceroy to march to Chancay.