Lothair II (supported by Pope Honorius II) asks Frederick II to restore to the crown the estates that he has inherited from Henry V. Frederick refuses, and by year's end a succession dispute breaks out between the House of Welf and the House of Hohenstaufen. The latter is led by Frederick and his brother Conrad III, duke of Franconia.
November – Jin–Song War: Emperor Taizong of the Jurchen-led Jin dynasty declares war on the Chinese Song dynasty – and orders his armies to invade Song territory. He sends the Western army to the city of Taiyuan in Shanxi province and the Eastern army to Bianjing (modern-day Kaifeng), the Song capital. The Song forces are not expecting an invasion and are caught off guard.[5]
^Steven Runciman (1952). A History of The Crusades. Vol II: The Kingdom of Jerusalem, p. 140. ISBN978-0-241-29876-3.
^Unité mixte de recherche 5648--Histoire et archéologie des mondes chrétiens et musulmans médiévaux. Pays d'Islam et monde latin, Xe-XIIIe siècle: textes et documents. Lyon: Presses Universitaires de Lyon.{{cite book}}: CS1 maint: numeric names: authors list (link)
^de Oliveira Marques, António Henrique (1998). Histoire du Portugal et de son empire colonial. Paris: Karthala. p. 44. ISBN2-86537-844-6.
^McGrank, Lawrence (1981). "Norman crusaders and the Catalan reconquest: Robert Burdet and te principality of Tarragona 1129-55". Journal of Medieval History. 7 (1): 67–82. doi:10.1016/0304-4181(81)90036-1.
^Mole, Frederick W. (1999). Imperial China: 900–1800, p. 196. Harvard University Press. ISBN978-0-674-01212-7.