The year 31 (AD 31) falls in the 1st century of the Common Era. In calendrical terms it is recorded as a common year that began on Monday under the Julian calendar. Contemporary Romans did not use numbered years as we do today but referred to years by the names of the serving consuls; this convention shaped how people of the time identified and recorded events.

Characteristics and dating

As with other years of the early Roman empire, AD 31 is located in a period governed by imperial administration and senatorial institutions. The Julian calendar, introduced by Julius Caesar in 45 BC, provides the basis for reconstructions of weekdays and year lengths. Scholars therefore describe AD 31 using the Julian framework and relate Roman consular dating to modern year numbering.

Notable events

  • The most consequential political episode of the year was the rapid fall of Lucius Aelius Sejanus, a powerful praetorian prefect whose arrest and execution precipitated a wide purge of his allies across the Roman state.
  • Following Sejanus's removal, the emperor consolidated authority by removing suspected conspirators, reshaping court politics and the position of the praetorian guard.
  • Local developments in provinces and cities continued as usual: administrative realignments, legal cases before governors, and economic activity persisted even while Rome underwent political turbulence.

Importance and legacy

The events of AD 31 illustrate the fragility of power based on personal networks within the early empire. The episode centered on the praetorian prefect highlighted how military and guard commanders could become kingmakers — and how swiftly they could be eliminated. Roman historians and later commentators used the year to discuss themes of ambition, imperial control, and the risks of concentrated influence.

For reference and further study, one can consult entries and chronologies that index years by consular names and cross-reference them with modern calendrical reconstructions. See the entries on the consulship system and imperial offices for context on how the Romans measured and remembered years.