en 817

817 in various calendars
Gregorian calendar	817; DCCCXVII
Ab urbe condita	1570
Armenian calendar	266; ԹՎ ՄԿԶ
Assyrian calendar	5567
Balinese saka calendar	738–739
Bengali calendar	224
Berber calendar	1767
Buddhist calendar	1361
Burmese calendar	179
Byzantine calendar	6325–6326
Chinese calendar	丙申年 (Fire Monkey); 3514 or 3307; — to —; 丁酉年 (Fire Rooster); 3515 or 3308
Coptic calendar	533–534
Discordian calendar	1983
Ethiopian calendar	809–810
Hebrew calendar	4577–4578
Hindu calendars
- Vikram Samvat	873–874
- Shaka Samvat	738–739
- Kali Yuga	3917–3918
Holocene calendar	10817
Iranian calendar	195–196
Islamic calendar	201–202
Japanese calendar	Kōnin 8; (弘仁８年)
Javanese calendar	713–714
Julian calendar	817; DCCCXVII
Korean calendar	3150
Minguo calendar	1095 before ROC; 民前1095年
Nanakshahi calendar	−651
Seleucid era	1128/1129 AG
Thai solar calendar	1359–1360
Tibetan calendar	阳火猴年; (male Fire-Monkey); 943 or 562 or −210; — to —; 阴火鸡年; (female Fire-Rooster); 944 or 563 or −209

Millennium:	1st millennium
Centuries:	8th century; 9th century ; 10th century;
Decades:	790s; 800s; 810s ; 820s; 830s;
Years:	814; 815; 816; 817 ; 818; 819; 820;

Events

Summer – Emperor Louis I issues an Ordinatio Imperii, an imperial decree that lays out plans for an orderly succession. He divides the Frankish Empire among his three sons: Lothair, the eldest, is proclaimed co-emperor in Aachen, and becomes the overlord of his brothers. He receives the dominion of Burgundy (including German and Gallic parts). Pepin, the second son, is proclaimed king of Aquitaine, and receives Gascony (including the marche around Toulouse and parts of Septimania); Louis (the youngest son) is proclaimed king of Bavaria, and receives the dominions of East Francia.
Prince Grimoald IV is assassinated by a complot of Lombard nobles vying for his throne.^[1] He is succeeded by Sico as ruler of Benevento (Southern Italy), who is forced to pay an annual tribute of 7,000 solidi to Louis I.

Ziyadat Allah I becomes the third Aghlabid emir of Ifriqiya (modern Tunisia). During his rule, the relationship between the Aghlabid Dynasty and the Arab troops remains strained.

January 24 – Pope Stephen IV dies at Rome after a 7-month reign, and is succeeded by Paschal I as the 98th pope of the Catholic Church.
Synod of Aachen: The council adopts a capitulare monasticum, containing the Benedictine rules of monastic life in the Frankish realm.