Venus Castina is a myth of a myth -- a modern re-imagining of the Roman goddess Venus.
"Venus Castina ('Chaste Venus') from Latin castus, is claimed to be an epithet of the Roman goddess Venus; in this form, she was supposedly associated with 'the yearnings of feminine souls locked up in male bodies'".
-Wikipedia, Venus Castina
The first recorded reference to Venus Castina is somewhat different in tone; in Otto Augustus Wall's 1920 book Sex and Sex Worship1, she is said to be "the goddess of indecency", and he claims that her temple was funded by the profits from the houses of prostitution. This is almost certainly a reference to the story of Greek lawmaker Solon using taxes he levied on brothels to build a temple to Aphrodite Pandemos, the Greek predecessor to Venus Erycina. (These were the crass aspects of the goddesses, fit for the common folk to worship, and things could get very rowdy on feast days.)
While Wall was the first to use this phrase in its full form, it appears that he got the term 'Castina' from Cesare Lombroso, who wrote in 18962 that:
"E si adoravano in Grecia ed in Roma la Venere divaricatrice, la Peribasia o cullatrice, la callipigia, la Lubrica cui si offrivano phalli in oro, e la Castina, la Venere dei sodomiti"
"And in Greece and Rome they worshipped the spreading Venus, the straddling3 or cradling, the callipygian4, the oiled5 to whom they offered golden phalli, and the chaste, the Venus of the sodomites."6
Unfortunately, no clue is given as to where he got this term from. However, this did not stop the rest of the world from quoting him -- time and time again, we are told that "At Rome, Cesare Lombroso tells us, the Venus of the sodomites received the title of Castina". At this point, it is worth remembering that Lombroso is not a historian, but rather a criminologist who was trying to establish that primitive peoples committed a lot of nasty crimes, in support of his theory that crime was the result of atavistic genetic factors. His review of crimes committed by uncivilized groups throughout history was brief but crowded with an overwhelming rush of unsubstantiated claims -- including the hasty one paragraph on ancient Greece and Rome, which is quoted in its entirety above.
While it appears that many writers have decided that Lombroso is the authority on Venus Castina -- despite the fact that he never used the phrase -- perhaps the most quoted text on the matter is the spuriously named Venus Castina: Famous Female Impersonators, Celestial and Human7 by Clarence Joseph Bulliet, a volume that contains no significant information on Venus Castina. Bulliet essentially uses her as a figurehead, and thus firmly ties her to transgenderism.
Since that point, the internet has become an echo chamber, with sites quoting each other back and forth, ignoring that she has no actual ties to Roman history. While the single most referred to site has been Wikipedia, Everything2 was one of the two sites that the original Wikipedia article, posted in 2007, cited as a reference. Apparently, this whole mess is mostly our fault.
1. Sex and Sex Worship (phallic Worship): A Scientific Treatise on Sex, Its Nature and Function, and Its Influence on Art, Science, Architecture, and Religion-with Special Reference to Sex Worship and Symbolism. by Otto Augustus Wall,
C.V. Mosby Company, 1920.
2. L'uomo delinquente in rapporto all'antropologia: alla giurisprudenza ed alle discipline carcerarie, Cesare Lombroso. 1896-1897, Volume 1
3. Aphrodite Peribasia is a reference to a statue of Aphrodite or Venus with the legs spread apart 'in straddling position'.
4. Lit. Venus of the shapely buttocks, Aphrodite Kallipygos in Greek, Venus Callipyge in Latin. It usually refers to a specific statue or its reproductions.
5. Lubrica may mean 'rubbed smooth' or 'lubricated'; however, it is also possible that this was intended to be a reference to Venus Libertina (an Epithet for Venus in which she represented women freed from slavery -- in the literal sense, as this was Rome). This label was sometimes confounded with lubentina, which had lascivious overtones. Lombroso may have been playing on this.
6. Translation mine. It probably contains errors.
7. Venus Castina: Famous Female Impersonators, Celestial and Human, Clarence Joseph Bulliet, 1928.