This article relies largely or entirely on a single source. (May 2019)
|903 by topic|
|Ab urbe condita||1656|
|Balinese saka calendar||824–825|
|Chinese calendar||壬戌年 (Water Dog)|
3599 or 3539
— to —
癸亥年 (Water Pig)
3600 or 3540
|- Vikram Samvat||959–960|
|- Shaka Samvat||824–825|
|- Kali Yuga||4003–4004|
|Japanese calendar||Engi 3|
|Minguo calendar||1009 before ROC|
|Seleucid era||1214/1215 AG|
|Thai solar calendar||1445–1446|
1029 or 648 or −124
— to —
1030 or 649 or −123
- King Berengar I of Italy proceeds to issue concessions and privileges to the Lombard nobility and monasteries. He grants concessions to Bobbio Abbey in Emilia-Romagna (Northeast Italy).
- King Louis IV ("the Child") promulgates the Raffelstetten customs regulations, a legal document for a toll-bridge on the Danube River in Asten (modern Austria).
- The Danish Vikings invade Anglesey after being driven out of Dublin (see 902). They fail to gain a foothold in Wales, and sail on to Chester.
- A party of Danes under the Viking warlord Ingimundr attack the Welsh in a pitched battle at Maes Ros Meilon, perhaps near Llanfaes.
- November 29 – Battle of Hama: Abbasid forces under Muhammad ibn Sulayman al-Katib defeat the Qarmatians near Hama, on the banks of the Orontes River (modern Syria). The Qarmatian army is scattered and pursued by Abbasid troops; Al-Husayn ibn Zikrawayh and other Qarmatian leaders are captured.
- March 6
- March 26 – Sugawara no Michizane, Japanese politician and poet (b. 845)
- June 10 – Cheng Rui, Chinese warlord
- July 27– Abdallah II of Ifriqiya, Aghlabid emir
- July – Benedict IV, pope of the Catholic Church
- December 24 – Hedwiga, duchess of Saxony
- December 30 – Tian Jun, Chinese warlord (b. 858)
- Adalhard of Babenberg, Frankish nobleman
- Moses Bar-Kepha, Syriac bishop and writer
- Théodrate of Troyes, Frankish queen (b. 868)
- Zhu Yanshou, Chinese governor (b. 870)
- "Benedict IV | pope". Encyclopedia Britannica. Retrieved May 7, 2019.