Dio states, in his narration of the first Trajan’s Dacian war, that an anonymous sister of Decebalus, the Dacian king, was captured by a character named Maximus, who can probably be recognized in Laberius Maximus, legatus of Moesia Inferior and chief in command of its provincial army.Surprisingly, this apparently un-influential episode has been reported as one of the causes of Decebalus’ surrender.The same shadow that surrounds the other characters of Dacian history is present also in this case, sources do not give any more information on Decebalus’ sister, nor her name and her history after the fall of Dacian kingdom.Since there are a large number of hypothesis to deal with, a series of different possibili-ties will be presented in order to find the most plausible explanation.Decebalus’s sister was probably involved, as wife of a barbarian chief, in a system of alliance strengthened with political marriages: her capture coincided with the collapse of Decebalus international network.

Keywords: Dacian Wars, international relations, Roman History, Cassius Dio, Decebalus.