Gaïnas (in Greek Γαινᾶς) is a general Goth ambitious with the service of the Roman Empire of the East under the reigns of Théodose I {{er}} and of Arcadius. He dies in December 400 after having been thorough with the escape via Eudoxie.

He begins his career like private, but order the barbarian quota of the army of Théodose against the usurper Eugene in 394 (See Bataille of the Cold River). In 395, it is combined with Stilicon and Eutrope to cause the fall of Rufin, and collects the fruits of them while becoming comes rei militaris . Named in 399 magister utriusque militiae , it is sent to fight the chief goth Tribigild, but gets along in fact with this last and thus causes the fall of Eutrope. The anti-Germanic faction of the court represented by Aurélien being temporarily seized the capacity, Gaïnas obtains the exile of this last, and with the support of Kaisarios, ex prefect of the court, it enters to Constantinople with an army of Goths. The religious opposition between Goths ariens and the orthodoxe population of the capital is poked by the patriarch Jean Chrysostome then by Synésios de Cyrène.

July 12th 400, excited by the empress Eudoxie who finds it too dangerous, the rabble massacres a quota of troops of Sheathed which, panicked, is withdrawn in Thrace. Another general goth, Fravitta is sent to his continuation, but Gaïnas is killed close to the Danube by the chief hun Uldin who returns his head to Constantinople on December 12th, 400. The party goth of Constantinople east thus demolishes and Arcadius celebrates this victory while making raise over the forum which bears its name a column whose low-reliefs represent the escape and the defeat of Goths de Gaïnas.