Early in his life his family moved to Serbia where after five years at high school in Kragujevac and Belgrade he enrolled in 1871 at the Serbian Military Academy.

During the Serbian-Turkish Wars (1876-1878) Petrović served first as the orderly officer of West Morava division (1876), then as a commander of a company.

It was rumored that his temporary retirement into civilian life was only taken since Petrović could not pass the exam for promotion to major but that he received that rank when he returned to the army as a high state official.

Petrović closely supported the young king Aleksandar when on April 1, 1893, he overthrew the regency and took control of the kingdom.

A group of army officers formed a conspiracy and during the night of 10–11 June 1903 entered the royal palace in Belgrade with the intention of overthrowing the unpopular King Aleksandar and Queen Draga.