The 9th century
2,505 sourced entries across 100 documented years, grouped into 10 decades. A century here runs 1900–1999 rather than 1901–2000, so its decades sit inside it exactly.
Decades
- The 800s — 10 years, 208 entries
- The 810s — 10 years, 222 entries
- The 820s — 10 years, 237 entries
- The 830s — 10 years, 219 entries
- The 840s — 10 years, 250 entries
- The 850s — 10 years, 245 entries
- The 860s — 10 years, 289 entries
- The 870s — 10 years, 300 entries
- The 880s — 10 years, 253 entries
- The 890s — 10 years, 282 entries
By subject
- Conflict & Security in the 9th century — 315 entries
- Religion & Belief in the 9th century — 194 entries
- Geopolitics & Diplomacy in the 9th century — 93 entries
- Exploration & Expansion in the 9th century — 57 entries
- Crime & Justice in the 9th century — 31 entries
- Culture & Society in the 9th century — 29 entries
- Climate & Environment in the 9th century — 21 entries
- Technology & Infrastructure in the 9th century — 15 entries
- Science & Discovery in the 9th century — 11 entries
- Health & Medicine in the 9th century — 11 entries
A few of the years
- 800June 28 – Ochk'in Kaloomte' Aj Ho' Baak becomes the new ruler of the Mayan city state of Machaquila in Guatemala and reigns until his death in 815.
- 812January 11 – Ex-emperor Staurakios, a son of Nikephoros I, dies of putrefaction in his wounds (see 811) in a monastery. He has reigned only two months and eight days, before being exiled by senior officials in Constantinople.
- 824March 3 – (9.19.13.15.19) (9th B'ak'tun, 19th K'atun, 13th year (Tun) 15th month (Winal) 19th day (K'in)) Juun Tsak-Took becomes the new ruler of the Mayan city state of Machaquila (in what is now Guatemala), along with co-ruler and Ti-Chaak become the after the death of Sihyaj K'in Ich’aak II. Juun Tsak-Tookwill until his 840.
- 836July 4 – Pactum Sicardi: Prince Sicard of Benevento signs a 5-year armistice with the duchies of Sorrento, Naples and Amalfi. He recognizes the trade of merchants among the three cities in Southern Italy.
- 848Pope Leo IV builds (on the opposite of the Tiber River) the Leonine City, a fortified three-kilometre wall that encircles the Vatican Hill and Borgo, to defend Rome.
- 860June 18 – Byzantine–Rus' War: A fleet of about 200 Rus' vessels sails into the Bosphorus, and starts pillaging the suburbs of Constantinople. The raiders set homes on fire, and drown and kill the citizens. Unable to do anything to repel the invaders, Patriarch Photios I urges his flock to implore the Theotokos to save the Byzantine capital. Having devastated the suburbs, the Rus' Vikings pass into the Sea of Marmara and attack the Isles of the Princes, plundering the local monasteries.
- 872May 18 – After his successful campaign against the Saracens, Louis II is crowned as Roman Emperor ("Emperor of the Franks") for the second time and converts the Muwalladun, and the Arab elite.
- 884January 6 – Hasan ibn Zayd, founder of the Zaydid Dynasty, dies after a 20-year reign at Amul. He is succeeded by his brother Muhammad, as emir of Tabaristan.