The name Katheryn is an English feminine form of the Greek name Katharine, which is derived from the ancient Greek name Aikaterine. This name can be traced back to the late 4th century AD, originating from the Greek words "katharos" meaning "pure" and "hagna" meaning "virginal" or "sacred".

The name gained widespread popularity throughout Europe during the Middle Ages, particularly after the cult of St. Catherine of Alexandria emerged in the 9th century. St. Catherine was a legendary virgin martyr from the early 4th century AD, known for her courage and erudition. Her story and legacy helped establish the name's association with purity, wisdom, and strength.

One of the earliest recorded examples of the name can be found in the 9th century AD, referring to St. Catherine of Alexandria. Throughout the Middle Ages, the name appeared in various spellings, including Katherina, Katerina, and Katrina, reflecting regional variations and adaptations.

In the 12th century, the name Katheryn became particularly popular in England after the Norman conquest, as it was embraced by the nobility and upper classes. It was also favored by the ruling houses of England, with notable figures such as Katherine of Aragon (1485-1536), the first wife of King Henry VIII, and Katherine Parr (1512-1548), the sixth and final wife of Henry VIII.

Another prominent figure bearing the name was Catherine de' Medici (1519-1589), the Queen of France and a powerful political figure during the Renaissance era. In the realm of literature, Katherine Mansfield (1888-1923) was a renowned New Zealand modernist writer known for her short stories.

Other notable individuals throughout history with the name Katheryn include Katherine Hepburn (1907-2003), the iconic American actress who won four Academy Awards, and Katherine Graham (1917-2001), the trailblazing American publisher who led The Washington Post during the Watergate scandal.