The Battle of Thermopylae in 254^[1][2] was a successful defense of the pass of Thermopylae by local Greek militia under Marianus, the Roman proconsul of Achaea, during an invasion of the Balkans by the Goths.^[3]

In 254 the Goths invaded and plundered Thrace and Macedonia.^[1][4][5] In 1979, Herwig Wolfram regarded 254 as the date, while Mallan and Davenport in 2015 suggested 262.^[6][1] Goltz and Hartmann estimated 254 as the date.^[2] David Potter in 2016 rejected Mallan and Davenport's estimate and dated it to either 253 or 259.^[4] The Goths attempted to storm Thessalonica with close order formations and assault columns.^[5] The Thessalonians mobilized to defend their city and beat off the attacks.^[5] The Goths abandoned the siege and moved off to invade Greece south of Thermopylae, seeking to loot the gold and silver wealth of Greek temples.^[5]

The Greeks learned of the Goths' approach and the Roman proconsul Marianus, the Athenian Philostratus, and the Boeotian Dexippus mobilized a militia to block the pass of Thermopylae.^[5] The militia were armed with bronze or iron-tipped wooden pikes, small spears, axes, and assorted weapons.^[5] They set to work fortifying the pass.^[5][1][4] Marianus gave a pre-battle speech to them, emphasizing the defense of the pass by previous generations of Greeks and Romans.^[5]

The Graeco-Roman forces successfully blocked the Goths' way at Thermopylae and the Goths returned home, albeit with considerable loot.^[7]

A fragment of text attributed to the contemporary historian Dexippus, discovered in Vienna in 2010, provides detail on the weapons, leadership, and geography of the engagement.^[8] The fragment cuts off before the battle's outcome.^[5] Dexippus was used as a source by the Byzantine chronicler George Syncellus, who mentioned the blocking of the pass and the Goths' return home with plunder.^[7]

• Goltz, Andreas; Hartmann, Udo (2008). "Valerian und Gallienus". In Johne, Klaus-Peter (ed.). Die Zeit der Soldatenkaiser. Krise und Transformation des Römischen Reiches im 3. Jahrhundert n. Chr. (235–284) (in German). Berlin: Akademie Verlag. ISBN 978-3-05-004529-0.
• Mallan, Christopher; Davenport, Caillan (November 2015). "Dexippus and the Gothic Invasions: Interpreting the New Vienna Fragment". Journal of Roman Studies. 105: 203–226. doi:10.1017/s0075435815000970. S2CID 163234044.
• Potter, David (2016). "War as Theater, from Tacitus to Dexippus". In Riess, Werner; Fagan, Garrett G. (eds.). The Topography of Violence in the Greco-Roman World. Ann Arbor: University of Michigan Press. ISBN 978-0472119820.
• Wolfram, Herwig (1990) [1979]. Geschichte der Goten. Entwurf einer historischen Ethnographie [History of the Goths]. Translated by Dunlap, Thomas J. University of California Press. ISBN 978-0520069831.

• Martin, Gunther; Grusková, Jana (2014) "'Dexippus Vindobonensis' (?) Ein neues Handschriftenfragment zum sog. Herulereinfall der Jahre 267/268" (in German)
• "The Vienna Dexippus (?) (second revised version)", uploaded by Jones, Christopher

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