Editing 1227 (section)

==== Europe ====
* Spring &ndash; [[Livonian Crusade]]: The [[Livonian Brothers of the Sword]] and their Crusader allies (some 20,000 men) cross the sea ice from mainland [[Estonia]], and defeat the last Estonian strongholds in the [[Battle of Muhu]] and the siege of the [[Valjala Stronghold]] in the [[Saaremaa]] islands. This marks the end of the Estonian campaign in the Livonian Crusade. The Sword Brothers conquer [[Danish Estonia]], and [[Tallinn]] is given town rights under [[Riga]] law.
* [[July 22]] &ndash; [[Battle of Bornhöved (1227)|Battle of Bornhöved]]: Count [[Adolf IV of Holstein]] – leading a coalition army from the cities of [[Free City of Lübeck|Lübeck]] and [[Hamburg]], defeats the Danish-German forces of King [[Valdemar II of Denmark|Valdemar II]], and the Welf nobleman [[Otto I, Duke of Brunswick-Lüneburg|Otto I]] ('''the Child'''). Adolf shakes off Danish supremacy and accepts an overlordship by the [[Prince-Archbishopric of Bremen|Archbishopric of Bremen]] under Archbishop [[Gerhard II (archbishop of Bremen and Hamburg)|Gerhard II of Lippe]]. Adolf expands his power and establishes new frontiers within the [[Holy Roman Empire]].
* [[July 28]] &ndash; [[Battle of Ane]]: Forces of the [[Prince-Bishopric of Utrecht|Bishopric of Utrecht]] are defeated by the rebellious Drenths led by [[Rudolph van Coevorden]] near [[Ane, Overijssel|Ane]] (modern [[Netherlands]]). The Drenths lure the Bishop's forces, supported by heavily armoured knights, in an ambush into a swampy area and kill Bishop [[Otto II of Lippe]]. After the battle, Otto's successor, [[Wilbrand van Oldenburg]], rouses the Frisian people into supporting the war against the Drenths.
* August &ndash; Emperor [[Frederick II, Holy Roman Emperor|Frederick II]] musters a German expeditionary force in [[Apulia]]. The crowded conditions and high heat contribute to discontent and disease among the assembled troops. On [[September 24]], an epidemic of [[malaria]] enfeebles the army at [[Brindisi]]. Several thousand Crusaders led by [[Henry IV, Duke of Limburg|Henry IV]], duke of [[Duchy of Limburg|Limburg]], and French and English mercenaries under the bishops [[Peter des Roches]] and [[William Briwere]], arrive at [[Acre, Israel|Acre]].<ref>[[Steven Runciman]] (1952). ''A History of The Crusades. Vol III: The Kingdom of Acre'', p. 150. {{ISBN|978-0-241-29877-0}}.</ref>  
* September &ndash; A second contingent joined by Frederick II, departs from Brindisi to the [[Levant]]. On [[September 11]], during the second day of the voyage, one of Fredericks' companions, [[Louis IV, Landgrave of Thuringia|Louis IV of Thuringia]], dies of an illness (possibly [[cholera]]) at [[Otranto]]. Frederick also becomes sick and decides to return home, while sending the rest of the Crusader fleet (20 galleys) to Acre. There, they fortify the coastal towns of [[Caesarea Maritima|Caesarea]] and [[Jaffa]].<ref>Hardwicke, Mary Nickerson (1969). ''The Crusader States, 1192–1243'', pp. 542–543. A History of the Crusades (Setton), Volume II.</ref>
* [[October 10]] &ndash; Frederick II recovering at [[Pozzuoli]], receives a letter from Pope [[Pope Gregory IX|Gregory IX]], announcing his ex-communication. Frederick is branded a wanton violator of his sacred oath taken many times, at [[Aachen]], [[Ferentino]], [[Veroli]] and [[Cassino#Medieval|San Germano]]. Meanwhile, the Crusader army fortifies [[Sidon Sea Castle]] and rebuilds [[Montfort Castle]], northeast of Acre, as a new headquarter castle for the [[Teutonic Order|Teutonic Knights]], who called it [[Starkenburg]].<ref>Van Cleve, Thomas C. (1969). ''The Crusade of Frederick II'', p. 447. A History of the Crusades (Setton), Volume II.</ref>
* [[Swedish–Novgorodian Wars|Swedish-Novgorodian War]]: Grand Prince [[Yaroslav II of Vladimir|Yaroslav II]] of [[Vladimir, Russia|Vladimir]] leads an attack from the [[Novgorod Republic]] on [[Baltic Finnic peoples]] in eastern [[Fennoscandia]], called "Yem", whom he devastates.<ref>{{cite web|url=http://193.184.161.234/DF/detail.php?id=6567|title=Attack to Finland in 1226|work= [[Laurentian Codex]]|language=sv|archive-url=https://web.archive.org/web/20070927051349/http://193.184.161.234/DF/detail.php?id=6567 |archive-date=2007-09-27}}</ref>
* [[November 24]] &ndash; Prince [[Leszek the White|Leszek I]] ('''the White''') is assassinated in an ambush on a council of Polish dukes in the city of [[Gąsawa]], an event which later becomes known as the [[Gąsawa massacre|Gąsawa Massacre]].