809

Year 809 (DCCCIX) was a common year starting on Monday of the Julian calendar, the 809th year of the Common Era (CE) and Anno Domini (AD) designations, the 809th year of the 1st millennium, the 9th year of the 9th century, and the 10th and last year of the 800s decade.

Events

Spring – Siege of Serdica: Krum, ruler (khan) of the Bulgarian Empire, captures the fortress of Serdica (modern Sofia), after a long siege.<ref>Theophanes Confessor. Chronographia, p. 485</ref> According to Byzantine sources, he massacres the garrison (supposedly 6,000 men), sacks the city, and razes the city walls, before returning with much loot to Bulgaria.Template:Sfn In the following years (and centuries), Serdica will serve as a base for the expansion of the Bulgars to the south of the Balkans.

A Byzantine fleet lands in the Venetian Lagoon, and attacks a Frankish flotilla at Comacchio, but is defeated. Doge Obelerio degli Antenori marries a Frankish bride, Carola; she becomes the first dogaressa of Venice.
Aznar Galíndez I succeeds Aureolus, as count of Aragon (modern Spain). He is installed by King Louis the Pious (a son of emperor Charlemagne), and remains a Frankish vassal.
A rebellion in Gharb al-Andalus (modern Portugal) is crushed by the Emirate of Córdoba.<ref>Template:Cite book</ref>

Caliph Harun al-Rashid of the Abbasid dynasty

March 24 – Caliph Harun al-Rashid dies at Tus, on an expedition to put down an uprising in Khorasan (modern Iran). He is succeeded by his son Muhammad ibn Harun al-Amin.

Emperor Heizei becomes ill, and abdicates the throne in favor of his brother Saga, who is installed as the 52nd emperor of Japan.<ref name="kunaichō2">Emperor Saga, Saganoyamanoe Imperial Mausoleum, Imperial Household Agency</ref>
Emperor Govinda III defeats his rival Nagabhata II, and obtains the submission of the Pala Empire (India).<ref>The Cambridge Shorter History of India, p. 143</ref><ref>Dynastic History of Magadha by George E. Somers, p. 179</ref>

Council of Aachen (809): Frankish bishops adopt the filioque addition in the Creed. Pope Leo III intervenes, and refuses to recognize it as valid.