Geopolitics & Diplomacy in the 12th century

132 sourced entries, 1100 CE to 1199 CE, oldest first. Also see Geopolitics & Diplomacy across every century or everything else in the 12th century.

• 1100October 18 – Reconquista: Peter I of Aragon conquers Barbastro (modern Spain) from the hands of the Almoravids.source
• 1100December 25 – Philip I of France elevates his son Louis VI as co-ruler to the government of the realm.source
• 1100Philip I of France conquers the Vexin area, and adds the city of Bourges and the province of Berry to his estate.source
• 1100The Ancestral Puebloans culture, located in the modern-day Four Corners (United States), rises (approximate date).source
• 1100In Iceland, the Althing decides that the laws should be transferred to a written form (approximate date).source
• 1101August 2 – By the Treaty of Alton, ratified at Winchester, Robert abandons his claim to the throne, recognising Henry as King of England.source
• 1101The county of Berg in Germany is established.source
• 1102The Pacta Conventa formed by the Croatian nobility, recognize King Coloman as their overlord, initiating the personal union between the two kingdoms. Coloman is crowned king of Croatia (until 1116).source
• 1105The Tamna Kingdom is annexed by the Korean Goryeo Dynasty.source
• 1108The consuls of Bergamo are first mentioned, indicating that the city has become an independent commune in Lombardy (Northern Italy).source
• 1108Autumn – The Principality of Nitra ceases to exist, after King Coloman of Hungary, deposes its last ruler, Álmos, duke of Croatia.source
• 1111October 5 – 18-year-old Baldwin VII succeeds his father, Robert II, as Count of Flanders until 1119.source
• 1112February 3 – Ramon Berenguer III ("the Great"), count of Barcelona, obtains the county of Provence through his marriage to the heiress, Douce I. Ramon's dominion stretches as far east as Nice (modern France).source
• 1112The Margraviate of Baden is founded by Herman II.source
• 1113September 7 – The Republic of Pisa signs a treaty with Ramon Berenguer III ('the Great'), count of Barcelona. The Pisan fleet embarks on a campaign against the Moors in the Balearic Islands.source
• 1113The Republic of Florence conquers the neighboring city of Montecascioli, as part of its effort to extend its domination over the contado (provinces of Italy).source
• 1115The Jin dynasty (1115–1234) (or Great Jin) is created by the Jurchen tribal chieftain Taizu (or Aguda). He establishes a dual-administration system: a Chinese-style bureaucracy to rule over northern and northeast China.source
• 1116The Zirid ruler of Ifriqiya, Ali ibn Yahya, conquers the island of Jerba, then acting as an independent piratical republic.source
• 1117Ramon Berenguer III ("the Great"), count of Barcelona, inherits Cerdanya (located between the Pyrenees and the Ebro River) which becomes part of the Principality of Catalonia.source
• 1117Vladislaus I, duke of Bohemia, abdicates in favor of his brother Bořivoj II, but retains much of the actual power.source
• 1118December 18 – Alfonso the Battler expels the Moors from Zaragoza. The Aragonese reconquer many of the valleys of the Jalón and the Jiloca.source
• 1118Gervais becomes Count of Rethel.source
• 1118Peace between England and Flanders is agreed upon.source
• 1118Wulgrin III becomes Count of Angoulême.source
• 1118The Genei era begins in Japan.source
• 1118Maelsechlainn Ua Faelain becomes King of the Déisi Muman in Ireland.source
• 1118The cantrefs of Rhos and Rhufoniog are annexed by Gruffudd ap Cynan, King of Gwynedd in Wales.source
• 1118Cu Faifne mac Congalaig becomes King of Uí Failghe in Ireland.source
• 1118Roman of Le Puy becomes lord of Oultrejordain.source
• 1118Joscelin I succeeds Baldwin of Le Bourg, as Count of Edessa.source
• 1118Alberich of Rheims becomes Master at the school of Rheims.source
• 1120The Pseudo-Ingulf's Croyland Chronicle records Cornwall as a nation distinct from England.source
• 1123February 25 – Japan's Emperor Toba abdicates in favor of his 3-year-old son Sutoku after a 16-year reign. The retired Emperor Shirakawa rules as regent during Toba's minority.source
• 1123September 27 – Prince Wuqimai of the House of Wanyan becomes the new Emperor of China after the death, on September 19, of his elder brother, the Emperor Taizu, founder of the Jin dynasty. Wuqimai is proclaimed the Emperor Taizong of Jin.source
• 1123The Pactum Warmundi: A treaty of alliance, is established between the Kingdom of Jerusalem and the Republic of Venice at Acre. The Venetians receive a street, with a church, baths and a bakery, free of all obligations, in every town of the kingdom. They are also excused of all tolls and taxes.source
• 1125The Republic of Venice pillages the islands of Rhodes, ravages Samos and Lesbos, and occupies Chios (controlled by the Byzantine Empire). The Republic of Florence sacks and conquers the neighboring independent republic of Fiesole in Italy.source
• 1126January 18 – Emperor Hui Zong of the Song Dynasty abdicates in favour of his eldest son, Qin Zong after a 24-year reign. Hui Zong assumes the honorary title of Taishang Huang (or "Retired Emperor").source
• 1126Summer – Emperor John II Komnenos re-confirms the treaty of 1082. This ends the hostilities with Hungary and Venice. John secures Braničevo, and recovers the region of Sirmium on the Danube, but is forced by Venice to renew the exclusive commercial privileges.source
• 1126Shrewsbury Castle is granted by King Henry I to his second wife, Queen Adeliza of Louvain (or Adelicia). The command of the castle is given to William FitzAlan.source
• 1127June 12 – Qinzong's younger brother, the 20-year-old Gaozong, re-establishes the Song dynasty (as the Southern Song dynasty) in Lin'an (modern-day Hangzhou) and is proclaimed emperor.source
• 1128January 15: Lý Dương Hoán became the king of Đại Việt, ascending to the throne as Emperor Lý Thần Tông.source
• 1128February – Saint-Omer and Ghent declare for Thierry (Theoderic) in his challenge to his cousin William Clito for the County of Flanders.source
• 1129April 20 – Gao Zong regains the throne (with the support of the imperial army led by General Han Shizhong). Zhao Fu is forced to abdicate with Meng having ruled for 25 days.source
• 1134The House of Brandenburg is founded, when Albrecht the Bear is made head of the Nordmark.source
• 1134Mas'ud becomes sultan of the Seljuk dynasty in Hamadan.source
• 1134Ermengarde becomes Viscountess of Narbonne.source
• 1135September – King García IV ("the Restorer") breaks with Alfonso VII, and makes common cause with the County of Portugal against Castile and León.source
• 1135October – Conrad III, duke of Franconia, gives up his title as King of Italy in opposition with Lothair III. He receives a pardon and recovers his estates.source
• 1135Lothair III receives a Byzantine embassy at his court, on behalf of Emperor John II Komnenos. It offers large financial subsidies for Lothair to start a campaign against Roger II. The negotiations will last for some months.source
• 1136February 5 – Treaty of Durham: A peace treaty is signed by Stephen and David I. The Scots are allowed to keep Carlisle and a part of Cumberland in return for stopping their advance. David refuses an oath of allegiance, as his loyalties rest with Matilda (daughter of the late King Henry I).source
• 1136May 28 – In Russia, the people of Novgorod depose and imprison Prince Vsevolod of Pskov. Novgorod asserts its independence from Kiev, but accepts protection from neighboring Kievan princes. In July, Vsevolod along with his wife and family are released (they are exiled to an uncle in Kiev).source
• 1136Sultan Mudzaffar Shah I establishes the Kedah Sultanate at Qodah Darul Aman (modern-day Kedah Darul Aman, Malaysia).source
• 1137August 11 – Ramon Berenguer IV, count of Barcelona, is married to Princess Petronilla of Aragon (only 1-year-old) – whose father, King Ramiro II of Aragon, seeks aid from Barcelona against King Alfonso VII of Castile, abdicates the throne in favor of Ramon on November 13.source
• 1137Egyptian military commander Ridwan ibn Walakhshi appointed Vizier in Egypt.source
• 1137The Ethiopian Empire is established by Emperor Mara Takla Haymanot of the Zagwe Dynasty.source
• 1138The Earldom of Pembroke, created for Gilbert de Clare, becomes the first earldom created by Stephen within the borders of Wales. Gilbert receives the rape and Pevensey Castle.source
• 1139January 25 – Godfrey II, Count of Louvain becomes Duke of Lower Lorraine.source
• 1139April 9 – The Treaty of Durham is signed, between Stephen, King of England and David I of Scotland.source
• 1139May – Representatives of Polvese Island formally submit the island to the city of Perugia, pledging military support, fiscal obligations, and an annual tribute of tench.source
• 1139July 25 – Treaty of Mignano: Pope Innocent II proclaims Roger II of Sicily as King of Sicily, Duke of Apulia and Prince of Capua.source
• 1140Summer – King Roger II promulgates the Assizes of Ariano (a series of laws to rule the Norman Kingdom of Sicily) after the pacification of southern Italy.source
• 1141November – The Jin dynasty and Southern Song dynasty sign the Treaty of Shaoxing, and peace in the Jin–Song Wars lasts for the next twenty years. The Huai River is established as the boundary between them.source
• 1142January 5 – Emperor Sutoku abdicates the throne after a 19-year reign and becomes a monk. He is succeeded by his 3-year-old brother Konoe, who accedes as the 76th emperor of Japan.source
• 1142May – Conrad III makes a peace agreement with the 13-year-old Henry the Lion at Frankfurt. He is appointed as duke of Saxony, which territories are deprived from his father, the late Duke Henry the Proud.source
• 1142August 31 - Suggested date of the founding of the Iroquois Confederacy.source
• 1142October 11 – Treaty of Shaoxing: The northern Jin Dynasty and Southern Song Dynasty sign a peace treaty, this ending the Jurchen campaigns against the Song Dynasty in China.source
• 1143October 5 – Treaty of Zamora: The Kingdom of Portugal is recognized by King Alfonso VII ("the Emperor") of León and Castile in the presence of his cousin, King Afonso I of Portugal and papal representatives.source
• 1145Spring – Arnold of Brescia, an Italian priest from Lombardy, turns Rome into a republic with a government patterned on that of the Roman Republic. Arnold becomes the intellectual leader of the Commune of Rome, calling for liberties and democratic rights after the deposition of Giordano Pierleoni.source
• 1146Władysław II ("the Exiled"), High Duke of Poland, suffers a defeat against the coalition forces under his brother Bolesław IV ("the Curly"). Władysław and his family escape across the border to Bohemia and later seek refuge in Germany. Bolesław captures Silesia and the Senioral territories, and becomes the new ruler of Greater Poland.source
• 1146Eldiguz, Seljuk ruler (atabeg) of Azerbaijan, founds the Eldiguzid Dynasty and establishes an independent state within the Seljuk Empire.source
• 1147The first known reference to Moscow as a meeting place of Rurikid princes Yuri Dolgoruky and Sviatoslav Olgovich.source
• 1147The Siculo-Normans take control of Gabes (modern Tunisia).source
• 1148King Afonso I ("the Great") of Portugal takes Abrantes from the Almoravids. Ramon Berenguer IV conquers the lower Ebro plain (between 1148–1149).source
• 1151Confronted with internal strife, the commune of Bologna is the first Italian republic to turn to the rule of a podestà, Guido di Ranieri da Sasso (it ends in 1155).source
• 1152Matlacohuatl becomes ruler of the city-state Azcapotzalco located in the Valley of Mexico (until 1222).source
• 1153November 6 – The Treaty of Wallingford: Henry of Anjou and Stephen ratify the terms of a permanent peace under the direction of Archbishop Theobald of Bec. Ending the civil war (The Anarchy) – between England and Normandy after 18-years. The treaty grants the throne to Stephen for the duration of his life, but makes Henry the heir apparent.source
• 1154Tallinn, the capital of Estonia, is first marked on the world map by Muhammad al-Idrisi.source
• 1154The Banate of Bosnia becomes an autonomous duchy as part of the Lands of the Hungarian Crown.source
• 1155Henry II grants the city of Bristol ('Brycgstow') a Royal charter, and is divided between Gloucestershire and Somerset (until 1373).source
• 1156September 17 – Frederick I makes the Margraviate of Austria a duchy and gives the Babenberg Dynasty special privileges (the Privilegium Minus).source
• 1157Albert I of Brandenburg begins his ruthless program to pacify the Slavic region.source
• 1158September 5 – Emperor Go-Shirakawa of Japan abdicates the throne after a 3-year reign. He is succeeded by his 15-year-old son Nijō as the 77th emperor. Go-Shirakawa retains power, and gives Kiyomori Taira a higher position to lead a samurai-dominated government.source
• 1159(Approximate date): Churchman Richard FitzNeal is appointed Lord High Treasurer in England, in charge of Henry II of England's Exchequer, an office he will hold for almost 40 years.source
• 1162July 24 – Emperor Gaozong of Song becomes embroiled in war again as hostilities resume with the Jurchen-led Jin dynasty (or "Great Jin") after 21 years of peace. Another peace treaty is signed, Gao abdicates the throne in favor of his adopted son Xiaozong. The smaller Southern Song empire becomes richer than the Song dynasty.source
• 1163Egyptian military commander Shawar appointed Vizier of Egypt for a second term.source
• 1165August 3 – Emperor Nijō of Japan abdicates the throne, dying soon after following a 7-year reign. He is succeeded by his 1-year-old son Rokujō as 79th emperor.source
• 1165In China the Jin dynasty ("Great Jin") and the Song dynasty make a lasting peace (until 1205).source
• 1166Henry II enacts the Assize of Clarendon, reforming English law, influential in the development of jury trial in common law countries worldwide.source
• 1167Taira no Kiyomori becomes the first samurai to be appointed Daijo Daijin, chief minister of the government of Japan.source
• 1167Diarmaid mac Murchadha (or Dermot), former king of Leinster, returns to Ireland with an advance party of Flemings under Richard fitz Godbert de Roche.source
• 1168King Valdemar I ("the Great") of Denmark conquers the Wendish capital at Arkona on the island of Rügen (modern Germany). The Wends become Christians and subject to Danish suzerainty.source
• 1169Eleanor of Aquitaine leaves the English court of Henry II, to establish her own court in Poitiers. It will become known as a center of courtly love. Richard I accompanies his mother and is made heir to Aquitaine.source
• 1169King Henry II of England and Louis VII of France sign a peace treaty which includes the betrothal of their respective heirs, the 11-year-old Richard of England and the 8-year-old Alys of France (or Alice).source
• 1170July 22 – Henry II and Thomas Becket meet near Fréteval, France, where they come to an agreement to end their differences. This results in Becket's partial restoration.source
• 1170December 1 – Becket controversy: Henry II sends word that his conflict with Thomas Becket is at an end, and his lands will be restored. Becket returns to England, landing at Sandwich.source
• 1170The Welsh prince Madoc (son of King Owain ap Gruffudd of Gwynedd) sails to North America, in his ship the Gwennan Gorn, and founds a colony.source
• 1171March 10 – King Amalric I of Jerusalem departs with a large staff for Constantinople. At Callipolis he is met by his father-in-law, John Doukas Komnenos, military governor (doux) of Cyprus. Amalric enters the Byzantine capital and is welcomed by Manuel I. In June, a treaty is signed, Amalric recognizes Manuel's suzerainty over Jerusalem.source
• 1171The successors of Robert Bordet leave Catalonia for Mallorca, marking the end of the attempts to create a Norman principality in Iberia.source
• 1173The Qiandao era ends and the Chunxi era begins during the reign of Emperor Xiao Zong of the Song dynasty.source
• 1174December 8 – The Treaty of Falaise: Captured by the English, William I is forced to sign a peace agreement. The treaty makes Scotland a feudal possession of England, William and his nobles swear allegiance to Henry II. He must hand over several castles to Henry in return for his freedom.source
• 1175Treaty of Windsor: High King Ruaidrí Ua Conchobair relinquishes his title and agrees to submit to Henry II as vassal of Connacht in Ireland.source
• 1175The Namayan Kingdom formed by a confederation of barangays, reaches its peak on Luzon (modern Philippines).source
• 1177August 1 – The Holy Roman Empire renounces any claims on the territory of Rome.source
• 1178King George III defeats a nobles' revolt and proclaims his 18-year-old daughter Tamar (the Great) as co-ruler of Georgia.source
• 1179King William I (the Lion) establishes two castles at the Beauly Firth and the Cromarty Firth in northern Scotland. On his return, the city of Aberdeen is chartered by Wiliam.source
• 1180January 13 – Henry the Lion, Duke of Saxony and Bavaria, is stripped of his duchies and all his imperial fiefs at an Imperial Diet in Würzburg for violating the king's peace. On April 13, Emperor Frederick I Barbarossa issues the Gelnhausen Charter, formally dissolving Henry's former domains. A portion of Saxony is reorganized as the Duchy of Westphalia, while other territories are granted to his ally, Otto I the Redhead, Duke of Bavaria.source
• 1180March 18 – Emperor Takakura is forced to abdicate by Taira no Kiyomori after a 12-year reign. He is succeeded by his two-year-old son, Emperor Antoku, who will reign until 1185. Kiyomori assumes control of the government, ruling as regent in the child emperor's name.source
• 1180The assembly traditionally considered the first Sejm of the Kingdom of Poland is convened at Łęczyca (approximate date).source
• 1181Jayavarman VII defeats the Chams and assumes control over the Khmer Empire (modern Cambodia).source
• 1182Mieszko III (the Old), duke of Greater Poland, agrees with his son Odon of Poznań to divide the territories between them: Mieszko hold his western lands and Odon receives the eastern lands south of the River Obra.source
• 1183June 25 – The Peace of Constance is signed, between Frederick Barbarossa and the Lombard League, forming the legal basis for the autonomy of the Italian city republics.source
• 1183Saladin conquers Syria and becomes sultan.source
• 1183Three-year-old Emperor Go-Toba ascends to the throne of Japan, after the forced abdication of his brother Emperor Antoku, during the Genpei War.source
• 1185July – Treaty of Boves: King Philip II of France signs a treaty to ensure his authority over his vassals, with Amiénois, Artois and other places in northern France passing to him. Philip is given the nickname "Augustus" by the monk Rigord for augmenting French lands.source
• 1185September – Henry the Lion, duke of Saxony, returns to Germany after being banished for three years by Frederick Barbarossa, Holy Roman Emperor.source
• 1185December – Retired Emperor Go-Shirakawa grants Minamoto no Yoritomo the authority to form the first bakufu (shogunate) in Japan, ending the Genpei War.source
• 1186The Byzantine Empire recognizes the independence of Bulgaria and Serbia.source
• 1188Spring – Henry II institutes legal reforms that give the Crown more control over the administration of justice. He orders Newgate Prison be built in London.source
• 1188The Cutting of the Elm: A meeting of Henry II and Philip II in the field at Gisors, in Normandy. It marks the Franco-Norman peace negotiations, following the Fall of Jerusalem (see 1187).source
• 1189February 18 – Emperor Xiaozong abdicates in favour of his son Guangzong as ruler of the Song dynasty. Xiaozong becomes a Taishang Huang ("Retired Emperor") and remains as the de facto ruler of China.source
• 1189August 29 – Ban Kulin, Bosnian ruler, writes the Charter of Ban Kulin, which becomes a symbolic "birth certificate" of Bosnian language and statehood.source
• 1189December 5 – King William I ("the Lion") of Scotland gives Richard I 10,000 marks to buy his kingdom's independence. This overturns the Treaty of Falaise which William had to sign when he was captured in 1174.source
• 1189Reconquista: King Sancho I of Portugal ("the Populator") turns his attention towards the Moorish small kingdoms (called taifas) and begins a campaign in the south of his kingdom. With the help of crusader forces he conquers the town of Silves. He orders the fortification of the city, builds a castle and styles himself "King of Silves".source
• 1189Winter – John awards land to Bertram de Verdun, a Norman nobleman, and grants Dundalk its charter with town privileges; it becomes a strategic Anglo-Norman stronghold in Ireland.source
• 1191The counties of Flanders and Hainaut (modern Belgium) are united under Count Baldwin VIII. Flanders, a feudal fiefdom of France, becomes an important, wealthy independent state of Western Europe.source
• 1192September 2 – After negotiations between Richard and Saladin, the Treaty of Jaffa is signed, which makes sure Jerusalem remains in Muslim hands, but insures visiting rights for pilgrims to come to the Holy City. The Third Crusade ends.source
• 1194July 24 – Emperor Guangzong of Song (or Zhao Dun) is forced to abdicate the throne to his 25-year-old son Ningzong, who succeeds him as ruler of the Song dynasty. During his reign, he will be dominated by his prime-minister Han Tuozhou (or Han T'o-Chou).source
• 1194Hubert Walter, vice-regent in the absence of Richard I, institutes the office of coroner to keep records of crown pleas. He also presides over the feudal judgment of John and makes an inquiry into land tenure.source
• 1194Hunac Ceel drives the Itza people out of Chichen Itza, forcing them to start the Itza Kingdom on Lake Petén Itzá (modern Guatemala).source
• 1195Temüjin, in alliance with the Jin dynasty of China, launches his first major campaign against the Tatars. This military action marks a new, formalized phase in Temüjin's rise to power and his ongoing unification of the various steppe tribes.source
• 1198February 18 – Emperor Go-Toba (or Toba the Second) abdicates the throne in favor of his two-year-old son Tsuchimikado, after a 14-year reign.source
• 1199Summer – King William the Lion of Scotland supports John's claim to the English throne, in exchange for ownership of the northern territories (including Northumberland and Cumberland).source