964
Year 964 was a leap year starting on Friday of the Julian calendar.
Events
Byzantine Empire
- Arab–Byzantine War: Emperor Nikephoros II continues the reconquest of south-eastern Anatolia. He recaptures Cyprus, and reorganizes the conquered lands into new themes. In the summer, they take the fortress cities of Anazarbus and Adana. Byzantine troops under General John Tzimiskes besiege Mopsuestia, but with the coming of winter he is forced to retreat to Caesarea.
- October 24–25 - Siege of Rometta: Nikephoros II sends an expedition to Sicily. The Byzantine army is sent to break the Muslim siege at Rometta, and to regain Sicily for the Byzantine Empire. For two days a battle takes place in the area between the beach and the besieged citadel of Rometta. The Saracens manage to defeat the Byzantine relief force.
Europe
- Spring - King Adalbert II returns to the mainland of Italy, and occupies the environs of Spoleto. Emperor Otto I leaves Rome with his army, and lays siege to the fortress city of Spoleto.
- Otto I proceeds on campaign in Italy, remaining in the environs of Lucca. In the fall he leaves plague-wracked Tuscany, and is forced to retreat to Liguria. His rearguard is attacked by Adalbert II.
By topic
Religion
- February - Pope John XII returns with his supporters to Rome. He convenes a synod that deposes Antipope Leo VIII who finds refuge at the court of Otto I. John dispatches a delegation under Otgar, bishop of Speyer, to negotiate an agreement.
- May 14 - Pope John XII dies after a 9-year reign. The Romans elect Benedict V, who is acclaimed by the city militia. He begins his pontificate as the 131st pope of the Catholic Church.
- June 23 - Benedict V is deposed and ecclesiastically degraded after Otto I besieges Rome. He starves the Romans into submission and restores Leo VIII to the papal throne.
Science
- Abd al-Rahman al-Sufi, a Persian astronomer, writes the Book of Fixed Stars