View source for 861

=== By place ===

==== Europe ====
* [[March]] &ndash; [[Robert the Strong]] is appointed [[margrave]] of [[Neustria]] by King [[Charles the Bald]]. He re-establishes the [[Marches of Neustria|Breton March]], and extends his remit by campaigning against [[Salomon, King of Brittany|Salomon]], duke 'king' of [[Duchy of Brittany|Brittany]]. Robert hires a combined [[Seine]]-[[Loire]] fleet for 6,000 pounds of [[silver]], 'before Salomon can ally with them against him'. In return, Salomon enlists 12 Viking ships under the command of [[Hastein]], to raid the county of [[Maine (province)|Maine]], which, with [[County of Anjou|Anjou]], becomes squeezed between Brittany and Neustria.
* Spring &ndash; The [[Council of Constantinople (861)|Council of Constantinople]], attended by 318 fathers and presided over by papal legates, confirms [[Photius the Great]] as patriarch, and passes 17 canons.
* [[Carloman of Bavaria|Carloman]], eldest son of King [[Louis the German]], revolts against his father. He is captured, but manages to escape to the [[Saxon Eastern March|Ostmark]] (or [[862]]).
* Summer &ndash; [[Vikings|Viking]] raiders sack the cities of [[Paris]], [[Cologne]], [[Aachen]], [[Worms, Germany|Worms]] and [[Toulouse]].

==== Abbasid Caliphate ====
[[File:Al-Mutawakkil.png|200px|thumb|right|[[Dirham]] [[Bust (sculpture)|Bust]] of Al-Mutawakkil. He was assassinated by his Turkic guards and his son on the night of 11 December 861]]
* [[December 11]] &ndash; Caliph [[al-Mutawakkil]] is assassinated by his [[Turkic peoples|Turkish]] guard, starting the period of troubles known as the "[[Anarchy at Samarra]]" (861–870). He is succeeded by his son [[Al-Muntasir]], as ruler of the [[Abbasid Caliphate]].
* [[Ya'qub ibn al-Layth al-Saffar|Ya'qub ibn al-Layth]], a Muslim military leader, starts rebelling against the Abbasids and founds the [[Saffarid dynasty|Saffarid Dynasty]] in the 870s. He rules over parts of [[Khurasan]] and eastern [[Iran]], and establishes his capital at [[Zaranj]] (modern [[Afghanistan]]).