1100

By place

Levant

• January - The Seljuk ruler Mahmud I is expelled from Bagdad by his brother Barkiyaruq, but Mahmud manages to retake the city, during his spring offensive.
• May or June - Raymond IV sails to Constantinople to obtain the support of Emperor Alexios I, in his attempt to seize Tripoli.
• August 1 - A Genoese fleets leaves Italy, to support the Crusaders' effort to conquer the coastal cities; the ships reach Latakia on September 25.
• August - Battle of Melitene: Bohemond I is captured by the Danishmends, leaving Tancred as regent of the Principality of Antioch for two years.
• August 20 - With the support of the Venetian fleet, the Crusaders under Tancred capture the coastal city of Haifa.
• December 25 - Baldwin I is crowned first King of Jerusalem at the Church of the Nativity in Bethlehem, by Daimbert, the new Latin Patriarch of Jerusalem, following the death of the previous ruler, Baldwin's brother Godfrey of Bouillon, on July 18.
• After a success over the Armenians of Cilicia and the Emirate of Aleppo, Baldwin of Bourcq becomes Count of Edessa, with the support of Daimbert.
• Genoa, Venice and Pisa gain trading privileges from the Crusader states, in return for their service during the conquest of the coastal cities.

  Europe

• August 2 - King William II dies in a hunting accident in the New Forest. Sir Walter Tirel is accused of having shot the arrow but flees the country to avoid a trial. Henry I claims the throne.
• August 5 - Henry I is crowned King of England, at Westminster Abbey. The power of the new monarch is ill-assured, and to mollify the barons he has to grant them the Charter of Liberties, one of the first examples of a written constitution in Europe.
• August 30 - After the failure of the Council of Liubech in 1097, the Congress of Vytechev establishes peace and the feudal system in Kievan Rus; the princes come to an agreement to share the country between them. Sviatopolk II of Kiev becomes the first Grand Prince.
• September 16 - Battle of Malagon: The Almoravid army defeats the Castellan troops.
• September 23 - Anselm, archbishop of Canterbury returns from exile, at the invitation of Henry I.
• October 18 - Peter I of Aragon conquers Barbastro from the hands of the Almoravids.
• November 11 - Henry I marries Matilda of Scotland, the daughter of King Malcolm III and a direct descendant of the Saxon king Edmund Ironside.
• Henry I grants the ownership of Carisbrooke Castle on the Isle of Wight to Richard de Redvers, a Norman nobleman.
• November 18 - The Council of Poitier opens, but is soon forcibly closed by William IX, duke of Aquitaine, as the bishops were about to excommunicate King Philip I once more.
• December 25 - Philip I elevates his son Louis VI as co-ruler to the government of the realm.
• In Iceland, the Althing decides that the laws should be transferred to a written form.
• Intense urban activity in north and central Europe: Kalmar and Varberg are chartered; The cities of Aach and Nakléřov in Bohemia are created. The castle of Burg Eppstein is built in central Germany.
• Philip I conquers the Vexin area, and adds the city of Bourges and the province of Berry to his estate.

  Africa

• Tuareg traders establish the city of Timbuktu north of Djenné along the Niger River. Timbuktu will later achieve fame as a center of Islamic learning. The Sankore, Djinguereber and Sidi Yahya mosques are among Timbuktu's most famous religious and scholarly institutions.

  China

• February 23 - Emperor Zhe Zong dies after a 15-year reign. He is succeeded by his 17-year-old brother Hui Zong as ruler of the Song Dynasty.
• In Kaifeng, capital of the Song Dynasty, is the number of registered citizens within the walls about 1,050,000. The army stationed there boosts the overall populace to some 1.4 million people.
• The Liao Dynasty crushes the Zubu, a tribute state of the Khitan Empire, and takes their khan prisoner.
• The Chinese population reaches about 100 million during the Song Dynasty.

  Americas

• Oraibi, a Hopi village in Navajo County, becomes the oldest populated settlement in modern-day Arizona.
• The Ancestral Puebloans culture, located in the modern-day Four Corners, rises.
• The city of Cusco is founded.

  By topic

Religion

• September 8 - Antipope Clement III dies at Civita Castellana after a 20-year reign in opposition to the legitimate popes Gregory VII, Victor III and Urban II. Supporters of Emperor Henry IV in Rome choose Theodoric as his successor.
• Frederick I becomes archbishop of Cologne, and begins the construction of the castle of Volmarstein.
• The Stift St. Georgen Abbey is founded near Sankt Georgen am Längsee.
• The Diocese of Faroe is founded.

  Technology

• Checkers is invented.