Caracalla's reign became notable for the Antonine Constitution (), also known as the Edict of Caracalla, which granted Roman citizenship to all free men throughout the Roman Empire. The edict gave all the enfranchised men Caracalla's adopted praenomen and nomen: "Marcus Aurelius". Domestically, Caracalla became known for the construction of the Baths of Caracalla, which became the second-largest baths in Rome; for the introduction of a new Roman currency named the "antoninianus", a sort of double "denarius"; and for the massacres he ordered, both in Rome and elsewhere in the empire. In 216, Caracalla began a campaign against the Parthian Empire. He did not see this campaign through to completion due to his assassination by a disaffected soldier in 217. Macrinus succeeded him as emperor three days later.