The Pompeian Era was a calendar era

Calendar era

A calendar era is the year numbering system used by a calendar. For example, the Gregorian calendar numbers its years in the Western Christian era . The instant, date, or year from which time is marked is called the epoch of the era...

 used by Hellenistic cities in Roman

Roman Empire

The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....

 Palestine, in particular the cities of the Decapolis

Decapolis

The Decapolis was a group of ten cities on the eastern frontier of the Roman Empire in Judea and Syria. The ten cities were not an official league or political unit, but they were grouped together because of their language, culture, location, and political status...

. The calendar counted the years from the region's conquest by the Roman general Pompey

Pompey

Gnaeus Pompeius Magnus, also known as Pompey or Pompey the Great , was a military and political leader of the late Roman Republic...

 in 63 BCE. Many of these cities had been self-governing poleis

Polis

Polis , plural poleis , literally means city in Greek. It could also mean citizenship and body of citizens. In modern historiography "polis" is normally used to indicate the ancient Greek city-states, like Classical Athens and its contemporaries, so polis is often translated as "city-state."The...

before the Jewish

Judaism

Judaism ) is the "religion, philosophy, and way of life" of the Jewish people...

 Hasmonean

Hasmonean

The Hasmonean dynasty , was the ruling dynasty of Judea and surrounding regions during classical antiquity. Between c. 140 and c. 116 BCE, the dynasty ruled semi-autonomously from the Seleucids in the region of Judea...

s had conquered them in the 2nd century BCE. The Romans restored their self-governing status, so the conquest amounted to a "new foundation" of the cities, and they made that date the epochal year

Epoch (reference date)

In the fields of chronology and periodization, an epoch is an instance in time chosen as the origin of a particular era. The "epoch" then serves as a reference point from which time is measured...

 of their calendars. Some other nearby cities, such as Philadelphia

Amman

Amman is the capital of Jordan. It is the country's political, cultural and commercial centre and one of the oldest continuously inhabited cities in the world. The Greater Amman area has a population of 2,842,629 as of 2010. The population of Amman is expected to jump from 2.8 million to almost...

, adopted the era even though they had never been under Hasmonean rule.

When archaeologists find Pompeian dates on a city's coins and inscriptions, they use them as evidence of the city's membership in the Decapolis league. However, some cities that ancient writers listed in the Decapolis did not use Pompeian dates. In particular, Damascus

Damascus

Damascus , commonly known in Syria as Al Sham , and as the City of Jasmine , is the capital and the second largest city of Syria after Aleppo, both are part of the country's 14 governorates. In addition to being one of the oldest continuously inhabited cities in the world, Damascus is a major...

 continued to reckon dates using the Seleucid era

Seleucid era

The Seleucid era was a system of numbering years in use by the Seleucid Empire and other countries among the ancient Hellenistic civilizations. The era dates from the return of Seleucus I Nicator to Babylon in 311 BC after his exile in Ptolemaic Egypt, considered by Seleucus and his court to mark...

.

The region continued to use the Pompeian era during the Byzantine

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

 period, long after the term "Decapolis" had fallen out of use. The calendar was used even after the Muslim conquest of Syria

Muslim conquest of Syria

The Muslim conquest of Syria occurred in the first half of the 7th century, and refers to the region known as the Bilad al-Sham, the Levant, or Greater Syria...

 in the 7th century CE. A church in Khilda, near Philadelphia (Amman

Amman

Amman is the capital of Jordan. It is the country's political, cultural and commercial centre and one of the oldest continuously inhabited cities in the world. The Greater Amman area has a population of 2,842,629 as of 2010. The population of Amman is expected to jump from 2.8 million to almost...

), is inscribed with the Pompeian year 750, or 687 CE

Common Era

Common Era ,abbreviated as CE, is an alternative designation for the calendar era originally introduced by Dionysius Exiguus in the 6th century, traditionally identified with Anno Domini .Dates before the year 1 CE are indicated by the usage of BCE, short for Before the Common Era Common Era...

, several years after the Muslim conquest.

Dates in the Pompeian Era

1 PE = 63 BCE

63 PE = 1 BCE

64 PE = 1 CE

699 PE = 636 CE (Battle of Yarmouk

Battle of Yarmouk

The Battle of Yarmouk was a major battle between the Muslim Arab forces of the Rashidun Caliphate and the armies of the East Roman-Byzantine Empire. The battle consisted of a series of engagements that lasted for six days in August 636, near the Yarmouk River, along what is today the border...

)

PE = CE