King Chlothar III of Neustria and queen regent Balthild found Corbie Abbey in Picardy (northern France), giving it immunity from taxation, and visits from local bishops in exchange for prayer.
Perctarit and Godepert become co-rulers of the Lombards, following the death of their father Aripert I. They split the kingdom, and establish their capital in Milan and Pavia (northern Italy).
Battle of Posbury: King Cenwalh of Wessex invades Dumnonia (south-west England). He is victorious over the native Briton tribes near Crediton in Devon, and drives them to the coast.
King Wulfhere of Mercia and his army sack the Berkshire Downs (south of Thame), and move south to conquer the Meonwara and the Isle of Wight.
Wulfhere appoints Æthelwealh as king of Sussex, and is baptized in Mercia. He receives the recently-conquered territories in modern-day Hampshire.
January 27 – Ali ibn Abi-Talib, first Shi'a Imam and the fourth caliph of the Rashidun Caliphate, is assassinated while at prayer at a shrine at Kufa (modern Iraq). According to the Shia Islam, his son Hasan ibn Ali succeeds him as the second Imam. According to the Sunni Islam, he is succeeded by Muawiyah I, age 59, who moves his seat of government to Damascus, and founds the Umayyad Caliphate.
Muawiyah I imprisons patriarch Giwargis I, after his refusal to pay tribute. The Christians are persecuted and their churches are destroyed (approximate date).
The imperial fleet of Japan invades Kyūshū by the order of Empress Saimei. On its way, princess Nukata composes a famous poem at Nikitatsu, in the province of Iyo (approximate date).
Saimei builds the palace of Asakura in Kyūshū, from trees cut down from the shrines. Two months later she dies. People say it is because the gods are angry for destroying the shrines.
Emperor Tenji ascends to the throne of Japan after Empress Saimei's death. He sends an expeditionary force under Abe no Hirafu to Korea, to help the allied kingdom of Baekje.
King Munmu becomes the 30th ruler of the Korean kingdom of Silla.
Maximus the Confessor, Christian monk, is recalled from exile in Thrace. He is tried, and sentenced to mutilation. His tongue and his right hand are cut off to prevent his further opposition to the Monothelites.
In Gaul all Roman bishops are replaced with Frankish bishops. They become increasingly common, as Frankish leaders control the episcopate (approximate date).
Ælfwine, king of Deira (approximate date)
Al-Hajjaj ibn Yusuf, Arab governor (d. 714)
Chen Zi'ang, Chinese poet and official (d. 702)
Liu Zhiji, Chinese historian (d. 721)
Muawiya II, Muslim caliph (d. 684)
February 12 – Ōku, Japanese princess (d. 702)
January 3 – Benjamin, Coptic Orthodox Patriarch of Alexandria
January 29 – Ali ibn Abi-Talib, first Shia Imam (b. 601)
February 17 – Finan, bishop of Lindisfarne
Aripert I, king of the Lombards
Cenberht, king of Wessex (approximate date)
Kōgyoku (also Saimei), empress of Japan (b. 594)
Landry, bishop of Paris (approximate date)
Year 661 (DCLXI) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. The denomination 661 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.