AD And BC

Stupid Question ™
Dec. 20, 2001
By John Ruch
© 2001

Q: How did people date events before the time of Jesus? When was the concept of AD and BC established?
—Anonymous


A: When civilizations feel the urge to group their years into eras, they have three main methods to choose from: the Anno Mundi (“Year of the World,” i.e., years since creation), Kingly Reigns or Arbitrary Lucky Name.

Kingly Reigns is the most popular. Most ancient peoples didn’t need lengthy chronologies and simply noted events as happening in Year X of the current monarch’s reign. The British Parliament still dates documents this way.

In many ways, the AD (Anno Domini, “Year of the Lord”) system is the ultimate example, with a king who happens to be immortal.

The Anno Mundi was used by the ancient Maya and now by the modern Jewish calendar, which reckons it’s been 5,762 years since Creation. Jews, however, have only been using the Anno Mundi since about the 1100s, probably under the influence of Bible-chronology-obsessed Christians.

For the previous 1,400 years, Jews had dated years by the Seleucid Era, beginning with the reign of Syrian Greeks over their homeland. In even more ancient times, they used their own kingly reigns, or sometimes the legendary Exodus from Egypt.

China and Japan used all three naming methods. Eras were given some mystical Lucky Name, like “Blessing Cloud” or “Great Treasure.” A new era was declared to go along with a new emperor, but the emperor could then declare new eras during his reign. Both countries traced the system back to legendary emperors who founded their nations. (The Chinese also used an independent, cyclical zodiac calendar for naming years, which you can find watered down on placemats in Chinese restaurants.)

Communist China now has a fixed era name that won’t change. Japan continues to use a system in which imperial reigns are eras, and the emperor can’t declare new eras. Right now in Japan it’s Heisei 12, the 12th year of Emperor Akihito’s reign. “Heisei” means something like “achieving peace.”

Ancient Rome used Kingly Reigns along with a sort of Anno Mundi—the Ab Urbis Condita (“From the Founding of the City”), dating things from Rome’s mythical founding by the wolf-children Romulus and Remus.

This “AUC” dating was still used by medieval scholars—including the Italian monk Dionysius Exiguus, who in 532 tried to untangle the knotty mess of figuring out when Easter should happen. He ended up reworking the entire Christian chronology from scratch, figuring (wrongly) that Jesus was born in 753 AUC. Then, imitating AUC (the years of which were called Anni Urbis Conditae), he named subsequent years as Anni Domini Jesu Christi—Years of the Lord Jesus Christ. It took 600 years for his AD system to become widely used.

BC (“Before Christ”) is apparently a later innovation and a necessary part of our history-conscious time. In almost all previous civilizations, there was no “before”; the era started as far into the mythological past as you’d ever want to go.