The Battle of São Mamede takes place on 24 June, 1128 near Guimarães and is considered the seminal event for the foundation of the Kingdom of Portugal.
Portuguese forces led by Afonso Henriques defeat forces led by his mother Teresa of León and her lover Fernão Peres de Trava.
Following São Mamede, the future king styles himself "Prince of Portugal".
He will be called "King of Portugal" in 1139 and be recognized as such by neighboring kingdoms in 1143.
