Chnodomarius, also Chnodomar, cognate to the Germanic Gundmar, was the king of an Alamannic canton in what is now south-west Germany, near the Rhine from sometime before 352 till 357. He seems to have had a recognized position among the other Alamanni.
During Magnentius' rebellion Chnodomar engaged in a battle with Magnentius' brother, Caesar Decentius, in 352, defeating him. Chnodomar may have been acting in concert with Constantius II, against whom Magnentius had rebelled.
In 357 after the Alamanni had forced Barbatio to retire from their territory, seven Alamanni kings united under the leadership of Chnodomar and brought a large force over the Rhine to engage Constantius' Caesar Julian. The armies met in the battle of Strasbourg (Argentoratum), and although the Romans were well outnumbered, they soundly defeated the Alamanni. Chnodomar was captured at the end of the battle. Julian spared his life and sent him off to Constantius. Eventually he died in exile in Rome.
- Drinkwater, p.201
- Cambridge Ancient History, v.13, p.54; Potter 2004:501.
- Cameron, Averil & Peter Garnsey editors, The Cambridge Ancient History, Volume 13. CUP, Cambridge, 1998. ISBN 0-521-30200-5
- Drinkwater, John F., The Alamanni and Rome 213-496 (Caracalla to Clovis), OUP Oxford 2007. ISBN 0-19-929568-9
- Potter, David S. The Roman Empire at Bay AD180-395, Routledge, New York, 2004, ISBN 0-415-10058-5