In the Middle Ages this name was common in England due to the popularity of medieval tales about the Trojan War. It subsequently became rare, but was revived in the 20th century.
It has only been commonly used as a given name since the 20th century, influenced by two plays featuring the character: William Butler Yeats' Deirdre (1907) and J. M. Synge's Deirdre of the Sorrows (1910).
The Cornish form of this name, Jennifer, has become popular in the English-speaking world.
Magenta was a character in “The Rocky Horror Picture Show” musical play and movie. She was a domestic maid played by Patricia Quinn.
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.