[2] Ancient sources variously identify Euphemia's paternal ancestry as Thracian (Evagrius Scholasticus, quoting Priscus)[3] or Illyrian (Theodorus Lector).

[2][5] In or around the year 453,[4] Euphemia married Anthemius, the son of Procopius, magister utriusque militiae ("Master of Soldiers of both armies", commander of both cavalry and infantry) of the Eastern Roman Empire from 422 to 424.

[6] Marcian granted his new son-in-law a series of honors and responsibilities, seemingly intended to prepare Anthemius for eventual elevation to the imperial office.

John Malalas states that Marcian took the final step and named Anthemius emperor of the Western Roman Empire, but this is considered an anachronism of the chronicler.

According to Priscus, Geiseric, King of the Vandals, having exhausted Sicily and Italia with a decade of raiding, began to expand his activities into the Eastern empire.