Capitalizing Age Names, Time Periods, and Centuries

Capitalization rules are often tricky and they can vary depending on what style you follow. Here are some examples of how to capitalize the names of historical periods (such as the Roaring Twenties) and century names.

Mignon Fogarty
1-minute read

capitalizing centuries

Ages and time periods with specific names are capitalized: 

  • the Bronze Age
  • the Middle Ages
  • the Jazz Age
  • the Roaring Twenties 
  • the Renaissance

On the other hand, if the name is simply descriptive, keep it lowercase. Examples from the AP Stylebook and the Chicago Manual of Style that stay lowercase except for the name of the country include 

  • ancient Greece 
  • classical Rome 
  • the colonial period 
  • the antebellum period 

Centuries Stay Lowercase

When you’re writing about centuries, the words remain lowercase; however, there is a difference between AP and Chicago style: 

  • 17th century (AP style)
  • seventeenth century (Chicago style)


“Centuries.” Chicago Manual of Style online, 16th edition. 9.33. http://www.chicagomanualofstyle.org/16/ch09/ch09_sec033.html (subscription required, accessed January 22, 2015).

“Descriptive designations for periods.” Chicago Manual of Style online, 16th edition. 8.71. http://www.chicagomanualofstyle.org/16/ch08/ch08_sec071.html (subscription required, accessed January 25, 2015).

“Traditional period names.” Chicago Manual of Style online, 16th edition. 8.72. http://www.chicagomanualofstyle.org/16/ch08/ch08_sec072.html (subscription required, accessed January 22, 2015).

“historical periods and events.” AP Stylebook online. http://www.apstylebook.com/online/?do=entry&id=1428&src=AE (subscription required, accessed January 22, 2015).

About the Author

Mignon Fogarty

Mignon Fogarty is the founder of Quick and Dirty Tips and the author of seven books on language, including the New York Times bestseller "Grammar Girl's Quick and Dirty Tips for Better Writing." She is an inductee in the Podcasting Hall of Fame, and the show is a five-time winner of Best Education Podcast in the Podcast Awards. She has appeared as a guest expert on the Oprah Winfrey Show and the Today Show. Her popular LinkedIn Learning courses help people write better to communicate better.