842

842 in various calendars
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	辛酉年 (Metal Rooster); 3539 or 3332; — to —; 壬戌年 (Water Dog); 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	Jōwa 9; (承和９年)
Javanese calendar	739–740
Julian calendar	842; DCCCXLII
Korean calendar	3175
Minguo calendar	1070 before ROC; 民前1070年
Nanakshahi calendar	−626
Seleucid era	1153/1154 AG
Thai solar calendar	1384–1385
Tibetan calendar	阴金鸡年; (female Iron-Rooster); 968 or 587 or −185; — to —; 阳水狗年; (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;

Year 842 (DCCCXLII) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar, the 842nd year of the Common Era (CE) and Anno Domini (AD) designations, the 842nd year of the 1st millennium, the 42nd year of the 9th century, and the 3rd year of the 840s decade.

Events

January 20 – Emperor Theophilos dies of dysentery at Constantinople, after a 12-year reign in which he expended much effort defending the eastern frontier against the invading Muslim Arabs. Theophilos is succeeded by his 2-year-old son Michael III, with his mother Theodora as regent and the 'temporary' sole ruler of the Byzantine Empire.^[1]
February 19 – The Medieval Iconoclastic Controversy ends, as a council in Constantinople formally reinstates the veneration of icons in the churches.

February 14 – Oaths of Strasbourg: King Louis the German, ruler of East Francia, and his half-brother Charles the Bald, ruler of West Francia, meet with their armies at Strasbourg. They agree to swear allegiance (recorded in vernacular languages) to each other, and to support each other against their brother Lothair I (nominal emperor of all the Frankish kingdoms and the Holy Roman Empire).^[2]
March 20 – King Alfonso II of Asturias (Northern Spain) dies after a 50-year reign, in which he undertook numerous campaigns against the Muslim armies of the Umayyad Emirate of Córdoba, and allied himself with the late Charlemagne. The childless Alfonso chooses Ramiro I, son of former king Bermudo I, as his successor.

Uurad of the Picts dies after a 3-year reign, and is succeeded by his son Bridei VI, who contests his power with rival groups, led by Bruide son of Fokel and Kenneth MacAlpin.
Vikings attack the Irish monastery at Clonmacnoise from bases in Ireland.

January 5 – Caliph Al-Mu'tasim dies at Samarra (modern Iraq), after an eight year reign. He is succeeded by his son Al-Wathiq, as ruler of the Abbasid Caliphate.

Abbasid caliph Al-Wathiq appointed his brother, Jaʽfar ibn Muhammad al-Mutasim (future al-Mutawakkil) as Leader of Hajj in 842.

January 5 – Al-Mu'tasim, Muslim caliph (b. 796)
January 20 – Theophilus, Byzantine emperor (b. 813)
March 9 – Humbert, bishop of Würzburg
March 16 – Xiao Mian, chancellor of the Tang Dynasty
August 16 – Death of Qaratis also known as Umm Harun, was the mother of Abbasid caliph al-Wathiq (r. 842–847). She died during her Hajj pilgrimage journey.
August 24 – Saga, emperor of Japan (b. 786)
October 22 – Abo, Japanese prince (b. 792)
Alfonso II, king of Asturias (b. 759)
Bernard of Vienne, Frankish bishop (b. 778)
Dúngal mac Fergaile, king of Osraige (Ireland)
Li Cheng, chancellor of the Tang Dynasty
Liu Yuxi, Chinese poet and philosopher (b. 772)
Sugawara no Kiyotomo, Japanese nobleman (b. 770)
Uurad, king of the Picts (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.

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	辛酉年 (Metal Rooster) 3539 or 3332 — to — 壬戌年 (Water Dog) 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	Jōwa 9 (承和９年)
Javanese calendar	739–740
Julian calendar	842 DCCCXLII
Korean calendar	3175
Minguo calendar	1070 before ROC 民前1070年
Nanakshahi calendar	−626
Seleucid era	1153/1154 AG
Thai solar calendar	1384–1385
Tibetan calendar	阴金鸡年 (female Iron-Rooster) 968 or 587 or −185 — to — 阳水狗年 (male Water-Dog) 969 or 588 or −184