World History


























BC and AD

People in different parts of the world have adopted many ways to mark the passage of time. The Chinese calendar counts years from the reign of the mythical Yellow Emperor in 2698 BC. The Islamic calendar numbers years from 622 AD when Muhammad fled from Mecca. Both calendars are based on lunar cycles. The year 2000 in our calendar is 4697 in the Chinese calendar and 1421 in the Islamic calendar.

Our solar calendar comes from ancient Egypt. It was modified during the middle ages in Europe, and it has been adopted by most of the world for official purposes. Years are numbered from the birth of Christ: years before year 1 are designated BC for “Before Christ;” years after year 1 are designated AD, an abbreviation for the Latin term Anno Domini, which means “in the year of the lord.” AD years are counted forward from year 1; BC years are counted backward from year 1. Thus, 500 BC was earlier than 200 BC.

In recent years, people who wish to avoid the reference to Christ have begun using the term BCE(Before the Common Era) to replace BC and CE(Common Era) to replace AD. The terms BCE and CE are found in some history books. These online lessons use the traditional terms BC and AD because they are more widely known in our culture, because there was no Common Era in history, and because non-Christians may object to the suggestion that the Christian era is the “common era” of humankind.

BC = before Christ; the negative numbers on a timeline.

AD = Anno Domini; the positive numbers on a timeline

Anno Domini = a Latin phrase which means “In the year of our Lord”. It is used to indicated dates that occurred after the birth of Jesus.