CE (Common Era)

A secular term equivalent to AD (Anno Domini, meaning "in the year of our Lord"). It is used to denote years after the birth of Jesus Christ. For example, 2023 CE is the same as AD 2023.

BCE (Before Common Era)

A secular term equivalent to BC (Before Christ). It is used to denote years before the birth of Jesus Christ. For example, 500 BCE is the same as 500 BC.

Century

A century is a period of 100 years.

• The 1st century includes the years 1 to 100.
• The 20th century includes the years 1901 to 2000.

Decade

A decade is a period of 10 years.

• The 1990s refers to the years 1990 to 1999.
• The 2000s refers to the years 2000 to 2009.

Millennium

A millennium is a period of 1,000 years.

• The first millennium includes the years 1 to 1000.
• The second millennium includes the years 1001 to 2000.

Key Historical Periods

Prehistoric

The period before written records began.

Ancient History

From the beginning of recorded history (around 3000 BCE) to the fall of the Western Roman Empire in 476 CE.

Medieval (Middle Ages)

From the 5th century CE to the late 15th century CE.

Early Modern Period

From the late 15th century CE to the late 18th century CE.

Modern Period