Mexican War of Independence
The fight at Oaxaca came at the same time as successful military coup in Spain against the monarchy of Ferdinand VII. Ferdinand was forced to reinstate the liberal Spanish Constitution of 1812. When that news reached Mexico, Iturbide saw it as an opportunity for the criollos to gain control of Mexico. After clashing with Guerrero's forces, Iturbide switched sides. He invited the rebel leader to meet to discuss a new independence struggle.