Afonso I Defeats Teresa of León at São Mamede

The Battle of São Mamede was a decisive conflict in which Afonso I of Portugal confronted the forces led by his mother, Teresa of León, and her companion, Fernando Pérez de Traba. Taking place near Guimarães, this battle was pivotal for the assertion of Afonso's authority over the County of Portugal. It ultimately resulted in a significant victory for Afonso, solidifying his control and laying the groundwork for the future independence and expansion of Portugal.