A late 16th-century drawing attributed to Jacopo Strada or his circle allows us to identify the original 'half-figure' female bust today in the Museo Civico of Casale Monferrato and coming from the collection of Cesare Gonzaga. The drawing's inscription confirms the correlation between the bust represented and that of the so-called Giulia Domna purchased by Gonzaga in Rome. A second female bust in the collections of the Museo, with identical provenance, has precise similarities with other heads that have been identified as representing the young Plautilla. The Casale portrait, previously ignored in the realm of iconographical study on Augusta, provides us with new elements in the much debated definition of the appearance of Caracalla's unfortunate wife.