|Covid-19|Salomon, duke ('king') of Brittany, is murdered by a faction which includes his son-in-law Pascweten and Gurvand, son-in-law of late ruler Erispoe. After Salomon's death they divide the country, and co-rule Brittany.
Svatopluk I, ruler (knyaz) of Great Moravia, concludes a peace treaty at Forchheim (Northern Bavaria). He is able to expand his territories outside the Frankish sphere, and subjugates the Vistulans.
Ingólfr Arnarson arrives from Norway, as the first permanent Viking settler in Iceland. He builds his homestead and founds Reykjavík. The settlement of Iceland begins (approximate date).
The Danish Vikings (from their base at Repton) drive King Burgred of Mercia into exile, and sack Tamworth. They conquer his kingdom and install his political opponent, Ceolwulf II, as sub-king.
Autumn – The Great Heathen Army splits into two bands; Halfdan returns with his forces to Northumbria, along with his brother Ubba, where he establishes a new base on the River Tyne.
Amlaíb Conung, the first Norse 'king' of Dublin, is killed in Scotland, during a campaign against his rival Constantin I (approximate date).
November – Frost begins in Scotland, and lasts until April 875.
Huang Chao, a salt privateer, joints forces with Wang Xianzhi to raise an rebel army at Changyuan (modern Xinxiang). The uprising weakens the Tang Dynasty further, which is already weakened by natural disasters—such as severe droughts and floods.
March 13 – The remains of Saint Nikephorus I are interred in the Church of the Holy Apostles, in Constantinople.
The monastery of Sevanavank is founded, located on the shore of Lake Sevan (Armenia).
Abu al-Hasan al-Ash'ari, Muslim scholar (d. 936)
Edward the Elder, king of Wessex (approximate date)
Constantine II, king of Scotland (approximate date)
Liu Yin, governor (jiedushi) of Southern Han (d. 911)
Lothar II, Frankish nobleman (d. 929)
May 10 – Meng Zhixiang, general of Later Tang (d. 934)
Wang Shifan, Chinese warlord (d. 908)
December 16 – Ado, archbishop of Vienne
August 15 – Altfrid, bishop of Hildesheim
Amlaíb Conung, Viking leader (approximate date)
Bayazid Bastami, Persian Sufi (approximate date)
Han Yunzhong, general of the Tang Dynasty (b. 814)
January 4 – Hasan al-Askari, 11th Shia Imam (b. 846)
Liu Zhan, chancellor of the Tang Dynasty
Lu Yan, chancellor of the Tang Dynasty (b. 829)
Pei Tan, chancellor of the Tang Dynasty
Salomon, duke ('king') of Brittany
Unruoch III, margrave of Friuli
Yahya II, Muslim sultan
Year 874 (DCCCLXXIV) was a common year starting on Friday (link will display the full calendar) of the Julian calendar.