Son of two fathers? Trajan and the adoption of emperorship in the Roman Empire

Abstract

Roman imperial succession was in practice a dynastic system. Since the Roman Empire had a high rate of child-mortality, many of the rulers did not have surviving biological sons. This made adoption a standard method of appointing an heir. There was, however, a clear preference for consanguineals when adopting someone into the imperial family. The only exception to this practice of adopting a family member as imperial successor was the adoption by the emperor Nerva (96–98) of Trajan (98–117). This article analyses some of the possible motives for this break with precedent, and the consequences for the ways in which imperial ancestry was represented. There was a noticeable emphasis on Trajan's biological father, the Elder Trajan, towards the end of the emperor's reign, but not similarly pronounced in all ancient ‘media’. Attention to the Elder Trajan was limited to Rome, where the new form of imperial adoption seems to have led to discussions about the relative merits of succession by adoption or through bloodline. These discussions are not traceable to the provinces, where images of imperial ancestry stuck to precedent. The mixed messages from the centre were apparently not sufficient to change local expectations.