In 27 BC Octavian Caesar, adopted son of Julius Caesar, assumed the title Augustus (revered one). This move is taken by historians as the beginning of the Roman Empire. Augustus, a title, has become the name by which Octavian is best known to history. Members of his family bore the name Caesar. Following the death of Augustus in 14 AD, Tiberius Caesar assumed the title Augustus and became emperor. Throughout the Julio-Claudian line (Augustus, Tiberius, Caligula, Claudius and Nero) the heir to the throne was a Caesar (his family name) but only one man, the emperor, bore the title Augustus. Following the death of Nero, last of the Caesar family, emperors continued to take both the names Caesar and Augustus as signs of their position. In 69, Vespasian Caesar Augustus became emperor and designated his sons Titus and Domitian as Caesars. Each would later become Augustus upon the death of his predecessor but coins were issued before they became emperor. This established a precedent that would continue for the next three centuries using the family name of Julius Caesar as a title for the heir to the throne. The emperor himself held both titles (Caesar and Augustus) the heir only Caesar. Interestingly, the title Caesar was not extended to the emperor's entire family but just to the heirs (some rulers gave the title to more than one son). Women were never Caesar but wives and daughters were titled Augusta.
Coins in the name of the heir to the throne were commonly issued bearing the title Caesar or its abbreviation CAES. Most typical is the center coin in our illustration showing Publius Septimius Geta (son of Septimius Severus) as CAES. Note the lack of the title Augustus or its abbreviation AVG. The portrait is a bust with bare head. Most emperors (Augusti) were shown wearing a laurel wreath which would never be used for a mere Caesar. On the left is a coin of Marcus Aurelius as Caesar under Antoninus Pius. At first glance the coin might appear to bear the legend AVG but the complete reading is AVRELIVS CAES AVG PII F or Aurelius Caesar son (filius) of the Augustus Pius. AVG refers to PII not to AVRELIVS. Again the portrait is bare headed. In this case the portrait is a head. After the time of Aurelius it was more common for Caesars to be shown as busts with heads (not showing clothing or shoulders) were reserved for the Augusti.
In 214 AD, a new denomination was introduced. The double denarius or antoninianus was distinguished by a radiate crown on the emperor. Antoniniani of Caesars were issued using the radiate crown. Our example (right) shows Philip II, son of Philip I, as Caesar. The oddity here is that the other use of the radiate crown, the double as or dupondius, was not issued for Caesars. It would seem that the decision was made that it was more important to distinguish the new denomination than to reserve the head decoration for the Augustus.
Caesar continued to be used as 'junior emperor and heir' under the Tetrarchal system of Diocletian. The title ceased to be used during the late 4th century when it became common to name heirs (even infants) directly to Augustus status.
(c) 2000 Doug Smith