For a brief time as a teenager, this emperor was married to the daughter of prefect Plautianus Plautilla. He was named Caesar after his father was victorious at the Battle of Lugdunum over Clodius Albinus. He is reputed to have allowed his army to slaughter citizens of Alexandria in retribution for mocking him and he was assassinated while traveling to a lunar shrine in Carrhae by Julius Martialis. His reign famously saw passage of the Constitutio Antoniniana, granting Roman citizenship to all freemen, and he was succeeded by Macrinus six years after killing his half-brother Geta. For 10 points, name this emperor who 
For a brief time as a teenager, this emperor was married to the daughter of prefect Plautianus Plautilla. He was named Caesar after his father was victorious at the Battle of Lugdunum over Clodius Albinus. He is reputed to have allowed his army to slaughter citizens of Alexandria in retribution for mocking him and he was assassinated while traveling to a lunar shrine in Carrhae by Julius Martialis. His reign famously saw passage of the Constitutio Antoniniana, granting Roman citizenship to all freemen, and he was succeeded by Macrinus six years after killing his half-brother Geta. For 10 points, name this emperor who ruled from 211 to 217 and built some baths.
For a brief time as a teenager, this emperor was married to the daughter of prefect Plautianus Plautilla.
Caracalla [or Lucius Septimius Bassianus]