842

842 in variouscalendars
Gregorian calendar	842; DCCCXLII
Ab urbe condita	1595
Armenian calendar	291; ԹՎ ՄՂԱ
Assyrian calendar	5592
Balinese saka calendar	763–764
Bengali calendar	249
Berber calendar	1792
Buddhist calendar	1386
Burmese calendar	204
Byzantine calendar	6350–6351
Chinese calendar	Tân dậuNăm (MetalRooster); 3539 or 3332; — to —; Nhâm tuất năm (WaterDog); 3540 or 3333
Coptic calendar	558–559
Discordian calendar	2008
Ethiopian calendar	834–835
Hebrew calendar	4602–4603
Hindu calendars
-Vikram Samvat	898–899
-Shaka Samvat	763–764
-Kali Yuga	3942–3943
Holocene calendar	10842
Iranian calendar	220–221
Islamic calendar	227–228
Japanese calendar	Jōwa9; ( thừa cùng ９ năm )
Javanese calendar	739–740
Julian calendar	842; DCCCXLII
Korean calendar	3175
Minguo calendar	1070 beforeROC; Dân trước 1070 năm
Nanakshahi calendar	−626
Seleucid era	1153/1154AG
Thai solar calendar	1384–1385
Tibetan calendar	Âm kim gà năm; (female Iron-Rooster); 968 or 587 or −185; — to —; Dương thủy cẩu năm; (male Water-Dog); 969 or 588 or −184

Millennium:	1st millennium
Centuries:	8th century; 9th century; 10th century;
Decades:	820s; 830s; 840s; 850s; 860s;
Years:	839; 840; 841; 842; 843; 844; 845;

Year842(DCCCXLII) was acommon year starting on Sunday(link will display the full calendar) of theJulian calendar,the 842nd year of theCommon Era(CE) andAnno Domini(AD) designations, the 842nd year of the1st millennium,the 42nd year of the9th century,and the 3rd year of the840sdecade.

Events

January 20– EmperorTheophilosdies ofdysenteryatConstantinople,after a 12-year reign in which he expended much effort defending the eastern frontier against the invadingMuslim Arabs.Theophilos is succeeded by his 2-year-old sonMichael III,with his motherTheodoraasregentand the 'temporary' sole ruler of theByzantine Empire.^[1]
February 19– The MedievalIconoclastic Controversyends, as a council inConstantinopleformally reinstates theveneration of iconsin the churches.

February 14–Oaths of Strasbourg:KingLouis the German,ruler ofEast Francia,and his half-brotherCharles the Bald,ruler ofWest Francia,meet with their armies atStrasbourg.They agree to swearallegiance(recorded invernacularlanguages) to each other, and to support each other against their brotherLothair I(nominal emperor of all theFrankish kingdomsand theHoly Roman Empire).^[2]
March 20– KingAlfonso II of Asturias(NorthernSpain) dies after a 50-year reign, in which he undertook numerous campaigns against theMuslimarmies of theUmayyad Emirate of Córdoba,and allied himself with the lateCharlemagne.The childless Alfonso choosesRamiro I,son of former kingBermudo I,as his successor.

Uuradof thePictsdies after a 3-year reign, and is succeeded by his sonBridei VI,who contests his power with rival groups, led byBruide son of FokelandKenneth MacAlpin.
Vikingsattack the Irish monastery atClonmacnoisefrom bases inIreland.

January 5– CaliphAl-Mu'tasimdies atSamarra(modernIraq), after an eight year reign. He is succeeded by his sonAl-Wathiq,as ruler of theAbbasid Caliphate.

Abbasid caliphAl-Wathiqappointed his brother, Jaʽfar ibn Muhammad al-Mutasim (futureal-Mutawakkil) asLeaderofHajjin 842.

January 5–Al-Mu'tasim,Muslimcaliph(b.796)
January 20–Theophilus,Byzantine emperor (b.813)
March 9–Humbert,bishop ofWürzburg
March 16–Xiao Mian,chancellor of the Tang Dynasty
August 16– Death ofQaratisalso known asUmm Harun,was the mother of Abbasid caliph al-Wathiq (r.842–847). She died during herHajjpilgrimage journey.
August 24–Saga,emperor ofJapan(b.786)
October 22–Abo,Japanese prince (b.792)
Alfonso II,king ofAsturias(b.759)
Bernard of Vienne,Frankishbishop(b.778)
Dúngal mac Fergaile,king ofOsraige(Ireland)
Li Cheng,chancellor of the Tang Dynasty
Liu Yuxi,Chinesepoetandphilosopher(b.772)
Sugawara no Kiyotomo,Japanesenobleman(b.770)
Uurad,king of thePicts(approximate date)
We Gyaltore Taknye,Tibetan nobleman
Zheng Tan,chancellor of the Tang Dynasty

^John Skylitzes,A Synopsis of Byzantine History, 811—1057: Translation and Notes,transl. John Wortley, 81note114.
^Pierre Riche,The Carolingians: The Family who forged Europe,transl. Michael Idomir Allen, (University of Pennsylvania Press, 1983), p. 162.