AD 827

827 in various calendars
Gregorian calendar	827; DCCCXXVII
Ab urbe condita	1580
Armenian calendar	276; ԹՎ ՄՀԶ
Assyrian calendar	5577
Balinese saka calendar	748–749
Bengali calendar	234
Berber calendar	1777
Buddhist calendar	1371
Burmese calendar	189
Byzantine calendar	6335–6336
Chinese calendar	丙午年 (Fire Horse); 3524 or 3317; — to —; 丁未年 (Fire Goat); 3525 or 3318
Coptic calendar	543–544
Discordian calendar	1993
Ethiopian calendar	819–820
Hebrew calendar	4587–4588
Hindu calendars
- Vikram Samvat	883–884
- Shaka Samvat	748–749
- Kali Yuga	3927–3928
Holocene calendar	10827
Iranian calendar	205–206
Islamic calendar	211–212
Japanese calendar	Tenchō 4; (天長４年)
Javanese calendar	723–724
Julian calendar	827; DCCCXXVII
Korean calendar	3160
Minguo calendar	1085 before ROC; 民前1085年
Nanakshahi calendar	−641
Seleucid era	1138/1139 AG
Thai solar calendar	1369–1370
Tibetan calendar	阳火马年; (male Fire-Horse); 953 or 572 or −200; — to —; 阴火羊年; (female Fire-Goat); 954 or 573 or −199

Millennium:	1st millennium
Centuries:	8th century; 9th century ; 10th century;
Decades:	800s; 810s; 820s ; 830s; 840s;
Years:	824; 825; 826; 827 ; 828; 829; 830;

Year 827 (DCCCXXVII) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar.

Events

June 14 – Euphemius, exiled Byzantine admiral, asks for the help of North African Arabs, to retake Sicily and Malta from the Byzantines.^[1] Emir Ziyadat Allah I of Ifriqiya promises to return the islands to Euphemius, in exchange for a yearly tribute, and sends an Arab Muslim expeditionary force of 10,000 men under the 70-year-old Asad ibn al-Furat, which lands at Mazara del Vallo in Sicily.
Fall – Siege of Syracuse: Muslim forces under Asad ibn al-Furat, in support of the rebel Byzantine army, besiege Syracuse, Sicily.^[2]

Summer – Omurtag, ruler (khan) of the Bulgarian Empire, launches an attack to the West, and penetrates into Pannonia. He expels the local chiefs, and installs Bulgar governors over the Slavic tribes to control them. Omurtag conquers the cities of Beograd, Braničevo, Sirmium, and most of eastern Slavonia.^[3]
Giustiniano Participazio deposes his younger brother Giovanni I, and is appointed doge of Venice. Giovanni, who is part of a pro-Frankish faction, is exiled to Zara (modern Croatia).

Æthelstan establishes himself as king of East Anglia, after killing King Ludeca of Mercia in battle. Ludeca is succeeded by Wiglaf, father-in-law (and probably distant cousin) of the late king Ceolwulf I's daughter.

Emperor Jing Zong is assassinated by a group of conspirators. He is succeeded by his brother Wen Zong, as ruler of the Tang Dynasty.

August 27 – Pope Eugene II dies after a 3-year reign, and is succeeded by Valentine as the 100th pope of the Catholic Church.
October 10 – Pope Valentine dies just after a two-month reign, and is succeeded by Gregory IV as the 101st pope of Rome.

Chalid Ben Abdulmelik and Ali Ben Isa travel to the Plain of Sinjar (modern Iraq), under orders of Caliph Al-Ma'mun, to measure the size of the Earth.

The Saracens, who found spinach originally in Persia (modern Iran), introduce the plant to Sicily.^[4]

^ Peter Sammartino and William Roberts, Sicily: An Informal History, p. 43.
^ Gilbert Meynier (2010) L'Algérie cœur du Maghreb classique. De l'ouverture islamo-arabe au repli (658-1518). Paris: La Découverte; p. 23.
^ John V.A. Fine, Jr. (1991). The Early Medieval Balkans: A Critical Survey from the Sixth to the Late Twelfth Century, p. 107. ISBN 978-0-472-08149-3.
^ Rolland, Jacques L.; Sherman, Carol (2006). The Food Encyclopedia. Toronto: Robert Rose. pp. 335–338. ISBN 978-0-778-80150-4.