📅 Today in HistoryJuly 4

Battle of Mantinea: The Thebans, led by Epaminondas, defeated the Spartans.

Marcus Licinius Crassus is granted a triump for his victory in Thrace.

Aelia Pulcheria takes a vow of chastity and is proclaimed Augusta, thus becoming the regent of the Byzantine Empire for her 13 year old brother Theodosius II after the death of the previous regent, praefect Anthemius.

Heraclonas and David, sons of Byzantine Emperor Heraclius, are proclaimed augustus and caesar respectively, possibly due to the bad health of their elder brother Heraclius Constantine.

Pactum Sicardi, a peace treaty between the Principality of Benevento and the Duchy of Naples, is signed.

Ulrich of Augsburg is canonized as a saint.

A supernova, called SN 1054, is seen by Chinese Song dynasty, Arab, and possibly Amerindian observers near the star Zeta Tauri. For several months it remains bright enough to be seen during the day. Its remnants form the Crab Nebula.

Jordan II of Capua is anointed as prince after his infant nephew's death.

The Crusades: Battle of Hattin: Saladin defeats Guy of Lusignan, King of Jerusalem.

Battle of West-Capelle: John I of Avesnes defeats Guy of Dampierre.