Due to the popularity of the saint, the name became common in the Christian world during the Middle Ages. The Normans brought it to England, where it was commonly spelled Cecily — the Latinate form Cecilia came into use in the 18th century.
This was a popular name in the 20th century (especially the middle decades) in French, German, and English-speaking countries. In the United States Christina has been more common since 1973, though both forms are currently floundering on the charts.
As an English given name, Christopher has been in general use since the 15th century. It became very popular in the second half of the 20th century, reaching the top of the charts for England and Wales in the 1980s, and nearing it in the United States.
In Denmark this name was borne by three kings (their names are usually spelled Christoffer), including the 15th-century Christopher of Bavaria who also ruled Norway and Sweden. Other famous bearers include Italian explorer Christopher Columbus (1451-1506), English playwright Christopher Marlowe (1564-1593), English architect Christopher Wren (1632-1723) and the fictional character Christopher Robin from A. A. Milne's Winnie-the-Pooh books.
The name was common in France during the Middle Ages, and was introduced from there to England, though it eventually became rare. Interest in it was revived by the character Melanie Wilkes from the novel Gone with the Wind (1936) and the subsequent movie adaptation (1939).
As an English Christian name, Noah has been used since the Protestant Reformation, being common among the Puritans. In the United States it was not overly popular in the 19th and 20th centuries, but it began slowly growing in the 1970s. Starting 1994 it increased rapidly — this was when actor Noah Wyle (1971-) began starring on the television series ER. A further boost in 2004 from the main character in the movie The Notebook helped it eventually become the most popular name for boys in America between 2013 and 2016. At the same time it has also been heavily used in other English-speaking countries, as well as Germany, the Netherlands, Scandinavia and France.
A famous bearer was the American lexicographer Noah Webster (1758-1843).
As an English name, it became popular due to the Fleetwood Mac song Rhiannon (1976), especially in the United Kingdom and Australia.
In the United States this name steadily grew in popularity through the 1950s and 60s. It shot up the charts after the release of the 1970 movie Ryan's Daughter. Within a few years it was in the top 20 names, where it would stay for over three decades. Famous bearers include the Canadian actors Ryan Reynolds (1976-) and Ryan Gosling (1980-).
Very rare as an American given name before 1980, it increased in popularity in the 1980s and 90s. It got a boost in 2004 after the debut of the television series Lost, which featured a character by this name.