A century is a unit of time equal to 100 years. Centuries are named using ordinal numbers, so we might refer to the 3rd century or the sixteenth century. Using this system it would be logical to assume that the first century refers to the earliest recorded time, but this is not the case.
Traditionally, the first century refers to the first 100 years after the birth of Christ, denoted with the abbreviation A.D. meaning Anno Domini (year of the Lord). Nowadays, this is often replaced with the secular C.E. meaning Common Era.
Centuries before Christ are denoted with the abbreviation B.C. meaning Before Christ. Today the secular B.C.E. meaning Before Common Era is often used instead.
It is important to understand how to name centuries correctly so that you can place a date in the correct century.
1st January 1 – 31st December 100
1st January 101 – 31st December 200
1st January 201 – 31st December 300
1st January 301 – 31st December 400
1st January 401 – 31st December 500
1st January 501 – 31st December 600
1st January 601 – 31st December 700
1st January 701 – 31st December 800
1st January 801 – 31st December 900
1st January 901 – 31st December 1000
1st January 1001 – 31st December 1100
1st January 1101 – 31st December 1200
1st January 1201 – 31st December 1300
1st January 1301 – 31st December 1400
1st January 1401 – 31st December 1500
1st January 1501 – 31st December 1600
1st January 1601 – 31st December 1700
1st January 1701 – 31st December 1800
1st January 1801 – 31st December 1900
1st January 1901 – 31st December 2000
1st January 2001 – 31st December 2100
The above list is the correct formal method of naming centuries. in reality, new centuries are widely celebrated a year early. this is because celebrating the change from 99 to 00 is more appealing psychologically.
Huge celebrations were held around the World on 31st December 1999 to mark the end of the century and the millennium.
Heather Y Wheeler. (2020). Centuries – How to Name Them. Available: https://www.historykeyskills.com/centuries-how-to-name-them/. Last accessed May 6th, 2021