📅 Today in HistorySeptember 17

Highest Galician nobility led by Pedro Fróilaz de Traba and the bishop Diego Gelmírez crown Alfonso VII as "King of Galicia".

The Battle of Myriokephalon is the last attempt by the Byzantine Empire to recover central Anatolia from the Seljuk Turks.

Louis the Great's daughter, Mary, is crowned "king" of Hungary.

Thirteen Years' War: A Polish army under Piotr Dunin decisively defeats the Teutonic Order at the Battle of Świecino.

The first Finnish-language book, the Abckiria by Mikael Agricola, is published in Stockholm.

The Treaty of Bergerac is signed between King Henry III of France and the Huguenots.

Polish-Ottoman War: The Ottoman Empire defeats the Polish-Lithuanian Commonwealth during the Battle of Cecora.

The city of Boston, Massachusetts, is founded in North America.

Sweden wins a major victory at the Battle of Breitenfeld against the Holy Roman Empire during the Thirty Years' War.

The Battle of Vilanova is fought between Portugal and Spain during the Portuguese Restoration War.