|Centuries:||4th century – 5th century – 6th century|
|Decades:||370s 380s 390s – 400s – 410s 420s 430s|
|Years:||406 407 408 – 409 – 410 411 412|
|409 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1162|
|Chinese calendar||戊申年 (Earth Monkey)
3105 or 3045
— to —
己酉年 (Earth Rooster)
3106 or 3046
|- Vikram Samvat||465–466|
|- Shaka Samvat||331–332|
|- Kali Yuga||3510–3511|
|Iranian calendar||213 BP – 212 BP|
|Islamic calendar||220 BH – 219 BH|
|Minguo calendar||1503 before ROC
|Seleucid era||720/721 AG|
|Thai solar calendar||951–952|
Year 409 (CDIX) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Honorius and Theodosius (or, less frequently, year 1162 Ab urbe condita). The denomination 409 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
- Spring – Gerontius, Roman general (magister militum), who had been a partisan of Constantine III revolts in Hispania. He elevates Maximus, his domesticus, as emperor.
- October 13 – The Vandals, led by king Gunderic, cross the Pyrenees into the Iberian Peninsula. They receive land from the Romans, as foederati, in Baetica (Southern Spain). The Alans occupy lands in Lusitania and the Suebi controlled parts of Gallaecia (modern Portugal).
- The Visigothic king Alaric I lays siege to Rome a second time, bringing the inhabitants close to starvation. Emperor Honorius, safe in inaccessible Ravenna, refuses to negotiate for peace, despite repeated offers from Alaric. He comes to terms with the Senate and sets up a rival emperor, Priscus Attalus, prefect (praefectus urbi) of the city.
- Honorius agrees that sons of prominent families at court in Ravenna be sent beyond the Danube as hostages; in return, later he calls up ten thousand Hun mercenaries.
- Famine strikes Hispania, Gaul and the Italian Peninsula.
- Ming Yuan Di, age 17, succeeds Dao Wu di as ruler of the Chinese Northern Wei (see Northern dynasties).
- Daniel the Stylite, Christian saint (approximate date)
- Liu Yikang, prince of the Liu Song Dynasty (d. 451)
- Gao Yun, emperor of Northern Yan
- Li, empress and wife of Gao Yun
- Mallius Theodorus, Roman consul (approximate date)
- Serena, noblewoman and wife of Stilicho
- Dao Wu Di, emperor of Northern Wei (b. 371)
- The End of Empire (p. 56). Christopher Kelly, 2009. ISBN 978-0-393-33849-2