"Imperial Portrait types were controlled by the imperial administration, aligned to and combined with propaganda messages such as military victories, or strength of the dynasty. Portraits were distributed to the people across the empire using different and parallel news media. Main news media were sculpture, paintings, medals, and coins. Roman coins of even the most shortlived emperors survived till today, as millions and millions of coins were issued, and people in ancient times proactively tried to hide them away due to their intrinsic metal value. Thus coins are a major source of information for Roman imperial portraits. Except the most esoteric usurpators [usurpers], all Roman Emperors and many of their family members had coins with their portraits issued." Source: The Roman Numismatic Gallery.