1170 CE
Anglo-Norman invasion of Ireland: Following a siege, combined Anglo-Norman and Irish forces seize the city of Dublin, forcing Ascall mac Ragnaill, last King of Dublin, into exile. Becket controversy: Thomas Becket excommunicates three bishops. 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.
Geopolitics & Diplomacy
- July 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
- December 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
- The 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
Conflict & Security
- September 21 – Anglo-Norman invasion of Ireland: Following a siege, combined Anglo-Norman and Irish forces seize the city of Dublin, forcing Ascall mac Ragnaill, last King of Dublin, into exile.source
- December 29 – Thomas Becket is assassinated by four knights (who believe themselves to be carrying out Henry II's wishes) in Canterbury Cathedral, after his refusal to be arrested for breaking his agreement with Henry II.source
- Fes in the Almohad Caliphate (modern Morocco) becomes the largest city of the world, taking the lead from Constantinople, capital of the Byzantine Empire.source
- Winter – Egyptian forces, led by Saladin, invade the Kingdom of Jerusalem, and besiege Darum on the Mediterranean coast. Its defenses are weak, and though Saladin has no siege engines with him, the fall seems imminent. King Amalric I withdraws his Templar garrison from Gaza, to assist him in defending Darum. Saladin raises the siege and marches on Gaza, where he captures the lower town (despite the stiff resistance ordered by Lord Miles of Plancy), and massacres the inhabitants. However, the citadel is too strong for Saladin, and he is forced to retreat to Egypt.source
- The palace guards massacre the civil officials at the Korean court of Goryeo and place Myeongjong as new ruler on the throne of the Goryeo dynasty.source
Exploration & Expansion
Religion & Belief
- June 14 – King Henry II has his 15-year-old son, Henry the Young King, crowned by Roger, Archbishop of York, as junior king and heir to the English throne. The coronation drives Pope Alexander III to allow the exiled Thomas Becket (whose privilege as Archbishop of Canterbury to crown English monarchs has been infringed) to lay an interdict on England as punishment, and this threat forces Henry to negotiate with Becket. Sir William Marshal is appointed tutor-in-arms to Henry the Young King.source
- November – Becket controversy: Thomas Becket excommunicates three bishops.source
- Pope Alexander III addresses a series of letters to the backward Swedish church. He wants to impose the strict canonical requirements on the Swedes, that is, the ecclesiastical legal system. Due to being Christianized in 1050, Sweden is having trouble to fully adapt to the Catholicism that is preached and acted on in Europe.source
Climate & Environment
- June 29 – 1170 Syria earthquake: One of the largest earthquakes to hit Syria. It forms part of a sequence of large earthquakes that propagate southwards along the Dead Sea Transform, starting with the 1138 Aleppo earthquake and continuing with the 1157 Hama, 1170 and 1202 Syria events.source
- This is the earliest date for the making of cheddar cheese in Somerset (this is according to a pipe roll of Henry II, who purchases 10,240 lb of cheddar at a farthing per pound).source
Births
- April 5 – Isabella of Hainault, queen of France (d. 1190)source
- May 9 – Valdemar II (the Conqueror), king of Denmark (d. 1241)source
- August 8 – Dominic, founder of the Dominican Order (d. 1221)source
- October 8 – Vladimir III Igorevich, Kievan prince (d. 1211)source
- Leonardo of Pisa, Italian mathematician (approximate date)source
- Ermengarde de Beaumont, queen of Scotland (d. 1233)source
- Amaury I, French nobleman (House of Craon) (d. 1226)source
- Lope Díaz II, Castilian nobleman (House of Haro) (d. 1236)source
- Saer de Quincy, 1st Earl of Winchester (approximate date)source
- Walther von der Vogelweide, German lyrical poet (d. 1230)source
- Ranulf de Blondeville, English nobleman and regent (d. 1232)source
- Bahauddin Zakariya, Ghurid scholar and poet (d. 1262)source
- Asukai Masatsune, Japanese waka poet and writer (d. 1221)source
- Eustace the Monk, French mercenary and pirate (d. 1217)source
Deaths
- January 22 – Wang Chongyang, Chinese philosopher (b. 1113)source
- April 23 – Minamoto no Tametomo, Japanese samurai (b. 1139)source
- May 6 – Lope Díaz I de Haro, Castilian nobleman (b. 1105)source
- May 21 – Godric of Finchale, English hermit and merchantsource
- July 25 – Reginald II of Bar (or Renaud), French noblemansource
- August 19 – Mstislav II Izyaslavich, Grand Prince of Kievsource
- September 6 – Qutb al-Din Mawdud, Zangid ruler of Mosulsource
- September 14 – Heilika of Lengenfeld, German countesssource
- November 18 – Albert I (the Bear), German noblemansource
- November 20 – Gerung of Meissen, German bishopsource
- December 20 – Al-Mustanjid, Abbasid caliph (b. 1124)source
- December 29 – Thomas Becket, English archbishopsource
- Eliezer ben Nathan, German rabbi and poet (b. 1090)source
- Hywel ab Owain Gwynedd, king of Gwyneddsource