In my search for examples of feminine names that have switched over to masculine names, I came across Kimberly.
The story starts way back with the Old English woman's name Cyneburg, which means “royal fortress”. St. Cyneburg was the daughter of 7th century King Penda, and she was the founder of an abbey in Northhamptonshire called Cyneburgecaestre (it’s now called Castor). Kimberley appears in the 1086 Doomsday book as a location name Chineburlai, meaning woodland clearing of the royal fortress. It became the location surname of residents of the area. Cyneburg did also carry on as a woman’s name in forms such as Kingburgh or Kinborough, and Kimbery through to the 17th century.
Skip ahead to 1890, John Wodehouse, 1st Earl of Kimberley lends his name to the mining town of Kimberley, North Cape, South Africa. A bit of a malicious compliance story on how they chose the name: “… John Wodehouse, 1st Earl of Kimberley, insisted that before electoral divisions could be defined, the places had to receive decent and intelligible names. His Lordship declined to be in any way connected with such a vulgarism as New Rush and as for the Dutch name, Vooruitzigt … he could neither spell nor pronounce it. The Colonial Secretary tasked with the job made quite sure that Lord Kimberley would be able both to spell and pronounce the name of the main electoral division by, as he says, calling it 'after His Lordship'. New Rush became Kimberley, by Proclamation dated 5 July 1873.”
The mining town was the site of the Siege of Kimberley in 1899 during the Boer War. It started to be given to boys and a few girls as either a famous battle name, or to commemorate a relative who died there. It was still pretty rare in the UK, about 30 boys and 10 girls were named Kimberley in the 10 years after the battle. About another 400 boys and girls were given it as a middle name.
This is where I have to explain the popularity of a completely different name: Kim. In the US, Kim was used as a short name for Kimball, an uncommon surname as first name used mainly by men in the US during the 19th century. In 1850, 245 Kimballs lived in the US. Kim itself started to get used rarely for boys after Rudyard Kipling’s book Kim was published in 1901. In that book, the boy is named Kim short for Kimball. For Kim in the UK, I didn’t find many examples and where I did, they were in Ireland and Scotland. Kim is also a man’s name in Scandinavian countries, short for Joachim.
There were both men and women with the first name Kim in the SSA database after 1900 but it started getting popular for girls after it appeared in Edna Ferber's 1926 novel Show Boat, where the protagonist names her daughter Kim after the first three letters of the American states: Kentucky, Illinois, and Missouri. It was a very rare unisex name until Kim took off for boys after the 1950 film adaption of the Kipling book, which starred Errol Flynn. There was also a character called Kim Parker, a female reporter in the 1949 Ma and Pa Kettle movie series. It got way more popular for girls in the late 50s, probably due to the influence of actresses Kim Hunter and Kim Novak, who both chose it as a stage name. Kim Hunter was in the 1951 movie A Streetcar Named Desire and Kim Novak was in Vertigo in 1958. Following right behind it was the name Kimberly. I didn’t find a reason why Kimberly took over. I am guessing it was considered the longer, formal form of Kim, despite Kim getting popular first (it peaked at #34 for girls and #98 for boys).
Kimberly was very popular for girls in the late 60s in the US and occasionally given to boys. It peaked for both at the same time although for boys it only reached #552. It peaked for girls in 1967 at #2 and has remained relatively popular ever since with a slow decline (It still ranks #184 in 2020). In the UK, New Zealand and Australia, the Kimberley spelling was more popular and shot up in popularity only in 1981, I’m guessing because of singer Kim Wilde (who was also just Kim, born in 1960 at the peak of Kim in the UK, so again more parents chose the ‘long form’ of a trending name). In Australia you are more likely to run into a Kim-just-Kim than a Kimberley, although the Kims will be older than the Kimberleys.
So although Kim could be seen as masculine short name that became feminine, Kimberly/Kimberley does appear to have feminine roots and to have at least been considered unisex since the beginning of its popular usage as a first name. Not quite a girl name on a boy, but also not a case of a boy name “going to the girls”.
