Wikipedia: Caracalla (/ˌkærəˈkælə/; 4 April 188 – 8 April 217), formally Marcus Aurelius Severus Antoninus Augustus, was the Roman emperor from AD 198 to 217. A member of the Severan Dynasty, he was the eldest son of Septimius Severus and Julia Domna. Caracalla reigned jointly with his father from 198 until Severus' death in 211. For a short time Caracalla then ruled jointly with his younger brother Geta, with whom he had a sour relationship, and whom Caracalla had murdered later in 211. Caracalla's reign was marked by domestic instability and external invasions from the Germanic people. Caracalla's reign was notable for the Antonine Constitution (Latin: Constitutio Antoniniana), also known as the Edict of Caracalla, which granted Roman citizenship to nearly all freemen throughout the Roman Empire. The edict gave all the enfranchised men Caracalla's adopted praenomen and nomen: "Marcus Aurelius". Domestically, Caracalla was known for the construction of the Baths of Caracalla, the second largest bath in Rome, for the introduction of a new Roman currency, the antoninianus, a sort of double denarius, and for the massacres he enacted against the people of Rome and elsewhere in the empire. Towards the end of his rule, Caracalla began a campaign against the Parthian Empire, a campaign he did not see through to completion due to his death in 217. Caracalla is presented in ancient sources as a tyrant and cruel leader, an image which has survived into modernity. Dio and Herodian present Caracalla as a soldier first and emperor second. In the 12th century, Geoffrey of Monmouth started the legend of Caracalla's role as the king of Britain. Later in the 18th century, Caracalla's memory was revived in the works of French artists due to the parallels between Caracalla's apparent tyranny and that of King Louis XVI. Modern portrayal of Caracalla is that of a psychopathic and evil ruler who was among the worst of Roman emperors.

I wonder if it is this tyranical attitude which led to there not being any complete statues of the emperor, except for (so far) this one. The small figure, in Parthian dress, is seen as an indication the statue was made in 217, shortly after the emperor was murdered during his campaign against that people.