When Peter Paul Rubens painted Portrait of Eusebia (?-360), wife of Emperor Constantius in 1609, he was engaging in a rare act: imagining a Roman empress whose likeness had not survived the centuries. The painting stands as one of the earliest modern attempts to reconstruct the image of Eusebia, a figure known from ancient texts but absent from the visual record. Rubens, fascinated by the personalities of late antiquity, drew on numismatic evidence and written descriptions to bring her to life for the Habsburg court, which prized such historical portraits as mirrors of imperial virtue.

The work's commission coincided with Rubens's return from Italy, a period when he was steeped in the grandeur of classical art and eager to demonstrate his command of both history and portraiture. Rubens captures Eusebia at a moment of poised dignity, her gaze steady and her hands lightly clasped over a scroll—perhaps alluding to her famed intelligence and influence at the court of Constantius II. The empress is draped in opulent fabrics, their folds rendered with Rubens's characteristic energy, while a delicate gold chain at her neck signals both status and restraint. Light falls across her face, animating her features and setting her apart from the dark, neutral background, a device Rubens often used to focus attention on the sitter’s psychological presence.

The scroll, an unusual prop for a female portrait of the time, hints at Eusebia’s role as advisor and protector of scholars, echoing the way Titian endowed his Isabella d’Este with attributes of intellect and power. The exact early history of Portrait of Eusebia remains uncertain, as records of its first owner have not survived. However, the painting is typical of the series of imaginary portraits Rubens created for erudite patrons in northern Europe, reflecting the period’s fascination with Rome and its rulers. Over the centuries, the work has been attributed variously to Rubens and his workshop, with recent technical analysis supporting its status as an autograph piece.

Today, it hangs in a major European collection, its subject still inviting speculation and admiration, and marking an early point in Rubens’s lifelong dialogue with the antique world.