Browse Historical Events by Month: What Happened in October?

King Cyrus "the Great" of Persia marches into Babylon, freeing Jewish captives and allowing them to return home.

Alexander the Great defeats Darius III of Persia in the Battle of Gaugamela, also called the Battle of Arbela. One of Alexander's finest victories and a major defeat for the Persians. More

The Battle of Alesia during the Gallic Wars takes place. The Rome military forces under the command of Julius Caesar surround and blockade the city of Alesia where the Gallic general Vercingetorix and his forces were sheltered. Caesar directed his troops to erect a series of extensive fortifications, including two walls encircling the city, to keep the defenders in and potential reinforcements out. Vercingetorix’s eventual surrender secured Roman authority over Gaul in its entirety. More

Marcus Junius Brutus, one of the conspirators in the assassination of Julius Caesar dies by suicide after being defeated in battle by Antony in Philippi. Greece.

Nero succeeds Claudius as Roman Emperor

The Siege of Jerusalem concludes with the sacking and destruction of the Second Temple by the Roman Empire.

Constantine the Great defeats Maxentius at the Battle of the Milvian Bridge, becoming the sole Roman Emperor. According to ancient sources, Constantine converted to Christianity just before the battle It was likely the reason for his decision to end Christian persecution and establish Christianity as the most favored religion within the Roman Empire.

Martin Luther posted his Ninety-five Theses against papal indulgences, or the atonement of sins through monetary payment, on the door of the church at Wittenberg, Germany. Within less than four years, the Catholic Church would brand Luther a heretic, and the Holy Roman Empire would condemn him as an outlaw. This marked the beginning of the Protestant Reformation, a turning point in history that would over time, transform not only the Christian faith, but also the politics and society of all of Europe. Some historians have argued that this event didn't happen as described but rather the Theses were delivered to the local archbishop. More

Persian king Cyrus (Achaemenid Empire), conquers Babylon, the ancient capital of the Neo-Babylonian (Chaldean) empire covering modern Iraq, Syria, Lebanon, and Israel. Many consider Babylon, the ancient literary, religious an science center,

The Battle of Tours takes place in France, where Frankish forces under Charles Martel defeat the Umayyad Caliphate, The large invading Islamic army was led by Emir Abdul Rahman Al Ghafiqi Abd al Rahman. During the battle, the Franks defeated the Islamic army and Emir Abd er Rahman was killed. This battle stopped the northward advance of Islam from the Iberian peninsula, and is considered by most historians to be of macro historical importance, in that it halted the Islamic conquests, during a period in which Islam was conquering the remains of the old Roman and Persian Empires. More

The Second Council of Nicaea is held, addressing the use of religious images in the Byzantine Empire.

The Great Heathen Army of Vikings attacks Rome, sacking the city and its surroundings.

The Battle of the Aisne takes place in present-day France, with Louis the Stammerer leading the West Franks against the Vikings.

The founding of the Fatimid Caliphate by Imam Al-Mahdi Billah in North Africa.

The Icelandic parliament, Althing, is established, making it one of the oldest extant parliamentary institutions in the world.

The construction of the Brihadisvara Temple in India is completed, dedicated to the Hindu deity Shiva.

Leif Erikson, the Norse explorer, is believed to have landed in North America, possibly in present-day Canada.

King Æthelred the Unready orders the St. Brice's Day massacre, leading to the killing of many Danes in England.

The Church of the Holy Sepulchre in Jerusalem is destroyed by the Fatimid Caliph Al-Hakim bi-Amr Allah.

The Battle of Hastings takes place, resulting in William the Conqueror's victory over King Harold II of England. More