📅 Today in HistoryJuly 25

Constantine I is proclaimed Roman emperor by his troops.

The Arch of Constantine is completed near the Colosseum in Rome to commemorate Constantine I's victory over Maxentius at the Milvian Bridge.

Climax of the Siege of Thessalonica by the Slavs in a three-day assault on the city walls.

The Edict of Pistres of Charles the Bald orders defensive measures against the Vikings.

Wang Geon becomes King of Goryeo after overthrowing Gung Ye in a coup the previous day

Eleanor of Aquitaine marries Prince Louis, later King Louis VII of France, at the Cathedral of Saint-André in Bordeaux.

Battle of Ourique: The Almoravids, led by Ali ibn Yusuf, are defeated by Prince Afonso Henriques who is proclaimed King of Portugal.

The city of Constantinople is recaptured by Nicaean forces under the command of Alexios Strategopoulos, re-establishing the Byzantine Empire.

The naval Battle of Algeciras takes place in the context of the Spanish Reconquista resulting in a victory for the Emirate of Granada and the Maranid Dynasty over the Kingdom of Castile.

The Battle of Molinella: The first battle in Italy in which firearms are used extensively.