Lucius Septimius Severus (reigned 193-211 A.D.) emerged as a military leader and was declared emperor in 193 A.D. Born in Leptis Magna, North Africa, and a veteran of several campaigns along the frontier of the empire, he sought to solidify his power within Rome by linking his family and future dynasty with that of the Antonines. In 196 A.D. he had himself retroactively adopted into the Antonine family. He then had his young son, Caracalla, declared Caesar in order to ensure his succession.
Modern scholarship has assigned the Emperor's portrait types to four distinct groups. Ours can be joined to the earliest portraits, the 'Accession type,' commissioned during his struggle for sovereignty. These early portraits closely linked the Emperor physically to the Antonines, and most specifically, Antoninus Pius. See p. 319-320 in Kleiner, Roman Sculpture and ch. 4 in McAnn, "The Portraits of Septimius (AD 193-211)," Memoirs of the American Academy in Rome.