840s

Template:Decadebox The 840s decade ran from January 1, 840, to December 31, 849.

Significant people

• Al-Mu'tasim
• Al-Wathiq
• Alfred the Great
• Louis the Pious
• Charles the Bald
• Ermentrude of Orléans
• Louis the Stammerer
• Louis the German
• Lothair I
• Kenneth I of Scotland
• Ragnar Lodbrok
• Michael III

References

Bibliography

• Template:Byzance et les Arabes
• Template:The Byzantine Revival, 780–842
• Template:EI2
• Jones, Gwyn (2001). A History of the Vikings. Oxford University. ISBN 978-0-19-280134-0.
• Kennedy, Hugh (2006). [[[:Template:Google Books]] When Baghdad Ruled the Muslim World: The Rise and Fall of Islam's Greatest Dynasty]. Cambridge, MA: Da Capo Press. ISBN 978-0-306814808.
• Sawyer, PH (2001). Illustrated History of the Vikings. Oxford University. ISBN 978-0-19-285434-6.
• Toynbee, Arnold (1973). Constantine Porphyrogenitus and His World. London and New York: Oxford University Press. ISBN 0-19-215253-X.
• Goldberg, Eric J. (2006). Struggle for Empire: Kingship and Conflict under Louis the German, 817-876. Ithaca, NY: Cornell University Press. ISBN 9780801438905.