princeps(Latin; “first one,” “leader”)

Unofficial h1 used by Roman emperors from Augustus (r. 27 BC–AD 14) to Diocletian (r. 284–305), a period called the principate. The h1 originated during the Roman republic, when it was held by the leading member of the Senate. Its use by Augustus strengthened his claim to be the restorer of republican institutions and virtues, though he and his successors were in fact autocrats. Seealso prince.

Learn more about princeps with a free trial on Britannica.com.