What do AD and BC mean, as well as CE and BCE?

A nativity scene with figurines representing the birth of Jesus, including Mary, Joseph, angels, shepherds, wise men, and animals, centered around baby Jesus in a manger.
A nativity scene of Jesus' birth. © History Skills

For anyone who wants to understand historical timelines, the abbreviations AD, BC, CE, and BCE can be pretty confusing.

 

You will often find these terms in history books and museums. Historians use these terms to divide human history.

 

Knowing what these labels mean helps us understand how they organize time and gives us a shared way to talk about the past.

AD and BC: The traditional system

BCE stands for 'Before Christ' and it refers to all the years that came before Jesus Christ's birth.

 

The numbers count backward from year 1, so 500 BC is earlier than 200 BC.

 

'Anno Domini', the Latin phrase which means 'in the year of our Lord', is what AD stands for.

 

Historians use AD for the years that followed Jesus's birth. From year 1, AD years move forward.

 

There is no year 0; the timeline moves directly from 1 BC to AD 1. Writers usually place AD before the year number, like AD 2024, but sometimes place it after, like 2024 AD.

 

In the 6th century, a monk named Dionysius Exiguus introduced this system. He also created a table that calculated Easter dates.

 

As the Christian calendar spread, Europe later adopted the system widely. People who study religious and Western history still use it today.

A timeline marking the division between BC (Before Christ) and AD (Anno Domini), centered on the birth of Jesus Christ. Numbers count down in BC and count up in AD.
AD and BC Timeline. © History Skills

CE and BCE: A more inclusive approach

To offer a more inclusive alternative to AD and BC, historians and scholars began using the terms CE and BCE in recent years.

 

CE means 'Common Era', and BCE means 'Before Common Era' is what BCE. These terms follow the same rules: BCE counts backward, and CE counts forward from year 1.

 

To discuss historical dates without referring to Christianity, CE and BCE help people who follow all faiths or none.

 

For example, someone might say '300 BCE' instead of '300 BC.' Or they might say '1066 CE' instead of 'AD 1066.'

 

In a world that includes many beliefs, these terms aim to be more neutral.

A timeline illustrating the division between BCE (Before Common Era) and CE (Common Era), with the birth of Jesus Christ marking the transition point at year 1. Numbers count down in BCE and up in CE.
CE and BCE Timeline. © History Skills

Does it matter which system you use in an assignment?

When you write an assignment, you should follow the rules that your teacher or school provided.

 

Some teachers prefer AD and BC. Others prefer CE and BCE as a more inclusive option.

 

As long as you stay consistent, either system usually works. Pick one system and use it throughout your assignment.


So why do some people say that AD means 'After Death'?

Some people who misunderstand history believe that AD stands for 'After Death', meaning after Jesus died.

 

This is not correct. 'Anno Domini' refers to the years after Jesus was born, and BC refers to the years before his birth.


Why do we use these systems?

Both systems help us understand history by dividing time into 'before' and 'after' based on a big event. In this case, it is the birth of Jesus.

 

 

Even though they use different names, all four terms serve the same purpose: to help us place events in order, whether we’re talking about ancient civilizations, empires, or important inventions. 

 

No matter which terms you use, they are intend to make history easier to understand and meaningful for everyone.