Winter of 1069–1070 – Harrying of the North: William I of England quells rebellions in the north of England, following an invasion by Sweyn II of Denmark. Widespread famine follows the devastation wrought.
Spring – King Sweyn II of Denmark joins English rebels, led by Hereward the Wake, and captures the Isle of Ely, in The Fens of eastern England.
April 11 – Archbishop of Canterbury Stigand is deposed.
June 1 – Hereward plunders Peterborough Abbey, in eastern England.
June – Denmark signs a treaty with England; Sweyn and his forces leave the country.
August 15 – The Pavian-born Benedictine Lanfranc is appointed as the new Archbishop of Canterbury in England.
An invasion of England by Malcolm III of Scotland is repelled.
Hugh d'Avranches, 1st Earl of Chester, the first Marcher Lord, invades Wales, capturing parts of Gwynedd.
A successful Byzantine counter-attack drives the Seljuq Turks across the Euphrates.
Bergen is founded by King Olaf III of Norway; it will function as the main city and capital of Norway, until it is replaced by Oslo in 1314.
Chinese Chancellor Wang Anshi starts the Xining Reforms (which last until 1085).
Jews from Rouen in Normandy settle in England, at the invitation of King William I.
The Temple of Literature, Hanoi, is established in the capital of Vietnam.
Uyghur poet Yusuf Khass Hajib of Balasagun, in the Kara-Khanid Khanate, completes the Kutadgu Bilig ("The Wisdom Which Brings Good Fortune"), and presents it to the prince of Kashgar.
Song dynasty Chinese astronomer, engineer, and statesman Su Song completes the compilation of the Ben Cao Tu Jing, a pharmaceutical treatise with related subjects of botany, zoology, mineralogy, and metallurgy.
Canterbury Cathedral in England is rebuilt, following a fire.
The rebuilding of York Minster in England begins.
Construction of Richmond Castle in North Yorkshire, England, by Alan Rufus begins.
Approximate date – Halsten Stenkilsson is deposed as king of Sweden, with Håkan the Red becoming king in Götaland, and Anund Gårdske being chosen as king of Svealand.
February 22 – Battle of Cassel: Robert the Frisian (son of Baldwin V) defeats his sister-in-law Richilde (widow of Baldwin VI) and her nephew Arnulf III in a succession struggle for the County of Flanders and is appointed count by King Philip.
March – Zaynab an-Nafzawiyyah marry Yusuf ibn Tashfin, leader of the Almoravids, and becomes his queen and co-regent.
April 15 – The Siege of Bari ends when Bari, the capital and last Byzantine-controlled city in the Catepanate of Italy, is captured by Italo-Norman forces under Robert Guiscard.
August 26 – Battle of Manzikert: The Byzantine Empire loses to an army of Seljuq Turks led by Alp Arslan. Byzantine civil war resulted in Turkish conquest of Anatolia.
William I of England defeats Hereward the Wake's rebellion on the Isle of Ely.
Edwin, Earl of Mercia, rebels against William I of England but is betrayed and killed, leading to the re-distribution of land within Mercia to William's subjects.
EuropeJanuary 10 – The Normans conquer Palermo in Sicily.
May 27 – The Accord of Winchester establishes the primacy of the Archbishop of Canterbury over the Archbishop of York in the Church of England.
June 29 – Romanos IV Diogenes, deposed ruler of the Byzantine Empire, is blinded and sent into exile at the Monastery of the Transfiguration, Kinaliada.
William I of England invades Scotland, and also receives the submission of Hereward the Wake.
Osbern FitzOsbern becomes Bishop of Exeter.
Dunfermline Abbey is founded – later to become the burial place of several Kings of Scots, including Robert the Bruce. The associated royal palace will be the birth place of King Charles I.
Alfonso VI becomes king of Leon and Castile following the assassination of his brother Sancho.
Divan'ı Lügat'ı Türk. An informative book written by Kaşgarlı Mahmut of Karakhanids to be presented to Caliph, about Turks.
AsiaThe Song dynasty Chinese polymath scientist and statesman Shen Kuo is appointed as the head official for the Bureau of Astronomy, where he begins his groundbreaking work with the colleague Wei Pu on accurately plotting the orbital paths of the stars, planets, and moon three times a night for a continuum of five years.
Shen Kuo is sent to supervise Chancellor Wang Anshi's program of surveying the building of silt deposits in the Bian Canal outside the capital city of Kaifeng. Using an original technique, Shen successfully dredges the canal and demonstrates the formidable value of the silt gathered as a fertilizer.
AsiaEmperor Shirakawa ascends to the throne of Japan.
Chancellor Wang Anshi of Song dynasty China creates a new bureau of the central government called the Directorate of Weapons, which supervises the manufacture of military armaments and ensures quality control.
The Seljuq Turks conquer Ankara.
EuropeSviatoslav II begins his reign as ruler of Kievan Rus.
Renewal of the treaty between the Christian king of Navarre, Sancho IV, and the Muslim ruler of the taifa of Zaragoza, al-Muqtadir.
Ebles II of Roucy leads a Frankish troop in Spain to support the king of Aragon in his struggle against his southern Muslim neighbors.
Arts and cultureRabbi Yitchaki Alfassi finishes writing the Rif, an important work of Jewish law.
ReligionApril 22 – Pope Gregory VII (Cardinal Hildebrand) succeeds Pope Alexander II as the 157th pope.
John IX bar Shushan ends his term as Syrian Patriarch of Antioch.
February 7 – Prince Pandulf IV of Benevento is killed while fighting the encroaching Normans in the Battle of Montesarchio.
November 25 – Magreb unites the Tengizi Islands, and becomes the first king of the Kingdom of Tengiz.
The Liao dynasty emperor rejects a proposal for all Khitan people to adopt surnames.
February – Pope Gregory VII holds a council that publishes a decree against lay investiture.
April – Pope Gregory VII publishes the Dictatus papae (Sayings of the Pope, aka the Dictates of Hildebrand), in which he asserts papal authority over earthly as well as spiritual rulers.
Revolt of the Earls: Three earls rebel against William I of England (William the Conqueror), in the last serious act of resistance to the Norman Conquest.
First Battle of Langensalza: Henry IV, Holy Roman Emperor defeats the Saxon nobles and subjugates Saxony.
The Liao dynasty version of the Buddhist Tripiṭaka is completed (approximate date).
Anund Gårdske is deposed as king of Svealand and king Håkan the Red of Götaland proclaims himself king of all Sweden.
The Seljuq Turks take Jerusalem from the Fatimids.
Lý dynasty forces under Lý Thường Kiệt defend Vietnam against invasion by Song dynasty China.
The Song dynasty Chinese polymath scientist and statesman Shen Kuo solves a heated border dispute with the Liao dynasty by dredging up old diplomatic records; he refutes Emperor Daozong of Liao's bluffs point for point during a meeting at Mt. Yongan (near modern Pingquan in Hebei), and reestablishes the Song's rightful borders.
January – The German bishops who have been invested by Henry IV, Holy Roman Emperor withdraw their allegiance from Pope Gregory VII.
February 14 – Pope Gregory VII excommunicates Henry IV, Holy Roman Emperor.
October 8 – Demetrius Zvonimir is crowned as King of Croatia in Solin (near Split) by a representative of Pope Gregory VII.
November 1 – In England a frost begins that lasts until April 1077.
December 25 – Polish King Bolesław II the Bold (Polish: Bolesław Śmiały) is crowned in Gniezno.
Anselm of Canterbury completes Monologion.
The Almoravids capture the Ghanaian capital of Kumbi.
Count Dirk V reconquers most of West Frisia (historical) from the bishop of Utrecht.
The Trial of Penenden Heath is thought to have been held, with an important ruling regarding land rights subsequent to the Norman Conquest of England.
Dmitar Zvonimir of Croatia donated the town of Vrana and Benedictine monastery of St. Gregory, as a sign of loyalty to Pope Gregory VII.
Vikramaditya VI deposes his older brother Someshvara II, and becomes king of the Western Chalukya.
Lý dynasty Vietnamese troops hold invading Song Dynasty Chinese forces at the Battle of Như Nguyệt River and a truce is concluded.
AfricaThe Almoravids complete the conquest of the Ghana Empire, and reach Spain.
AsiaThe Seljuk Turks capture Nicaea.
Suleyman I of Rûm becomes the leader of the Seljuk Sultanate of Rûm in modern Turkey.
Anushtegin Gharchai becomes, as a Seljuk vassal, leader of the Khwarezmid Empire.
EuropeJanuary 26 – Walk to Canossa: Henry IV, Holy Roman Emperor, visits Pope Gregory VII as a penitent, asking him to remove sentence of excommunication.
January 28 – The excommunication of Henry IV, Holy Roman Emperor is lifted.
The first Parliament of Friuli is created.
Henry IV, Holy Roman Emperor grants the county of Friuli, with ducal status, to Sigaerd, Patriarch of Aquileia.
Robert Curthose instigates his first insurrection against his father, William the Conqueror, in Normandy.
The kingdom of Duklja is founded.
The first recorded Trial by combat is held in England.
Vsevolod of Kiev becomes the prince of Kievan Rus'.
Alfonso VI of Castile conquers Coria.
Pope Gregory VII places the island of Corsica under the secular rule of the archbishop of Pisa.
Hugh of Burgundy supports the king of Aragon in his conquest of the castle of Muñones from the emir of Zaragossa.
ArtsThe Bayeux Tapestry is made.
ReligionThe first English Cluniac Benedictine priory is established, at Lewes.
Paul of Caen is installed as Abbot of St Albans in England; the building of St Albans Abbey Church commences.
Pope Christodolos of Alexandria ends his reign as Coptic Pope.
Dionysius V Lazaros becomes Syriac Orthodox Patriarch of Antioch.
EuropeJuly 11 – Romanesque tympanum of Santiago de Compostela Cathedral in Galicia (Spain) is constructed.
August 7 – Battle of Mellrichstadt was fought between Holy Roman Emperor Henry IV and the German anti-king Rudolf of Swabia.
Anselm is elected abbot of Bec Abbey in Normandy.
Approximate date – The White Tower of the Tower of London is begun under the direction of Bishop Gundulf of Rochester.
AsiaAt the Battle of Kalavrye, the Byzantine imperial forces of general Alexios I Komnenos are victorious over the rebellious governor of Dyrrhachium, Nikephoros Bryennios the Elder.
Philaretos Brachamios abandons his claim to the Byzantine empire on being appointed duke of Antioch, a foundation of the later Armenian Kingdom of Cilicia.
By this year, the iron industry in Song dynasty China is producing a total weight of 127,000,000 kg (125,000 t) of iron product per year.
AfricaThe Almoravid emir, Yusuf ibn Tashfin besieges Ceuta. Since the city can receive help from the sea, the siege will last until 1083.
April 11 – Murder of Stanislaus of Szczepanów (Pol. Stanisław ze Szczepanowa), Bishop of Kraków, personally by Bolesław II the Bold, King of Poland, who flees the country, leaving his brother Władysław I Herman to succeed him.
Persian astronomer Omar Khayyám computes the length of the year to be exactly 365.24219858156 days, the most accurate calculation of his time. Khayyam also, in Treatise on Demonstrations of Problems in Algebra, produces a complete classification of cubic equations and their geometric solutions.
Upon the death of Håkan the Red, Halsten returns as king of Sweden, jointly with his brother Inge the Elder.
William I of England establishes the New Forest.
Constance of Burgundy founds a monastery in Burgos.
William the Conqueror