Sorry, but the the simple answer is “no”. This is a false etymology for the word. This myth has been explained in many places online already but like any good urban legend it refuses to die anytime soon so let’s have another stab at it…
There are several origin stories for this etymology. One popular example is that the term dates back to the middle ages, when sex was allegedly illegal between unmarried people who required consent of the King before engaging in the act. If consent was given, they were presented with a sign that said F.U.C.K. which they were to hang on their door while they performed the act.
And you thought today’s government was bureaucratic!
There are a few variant forms of the alleged acronym, including Fornication Under Consent of the King, and Fornication Under Christ, King.
Most sites date the acronyms to the internet circa 1995 although For Unlawful Carnal Knowledge was the title of the 1991 album by Van Halen. The term was also used on a song by the band Coven on their 1969 album Witchcraft Destroys Minds & Reaps Souls. It’s likely that the acronym is a joke that dates back to World War I.
However, fuck isn’t an acronym at all. This faux history was created after the word emerged, so some call it a backronym.
Where the fuck did fuck come from? The etymology is uncertain, but it’s probably of Germanic origins. It is possible that fuck is derived from Dutch fokken (“to breed, to beget”), German ficken (“fuck” and earlier, “make quick movements to and fro”), Norwegian dialectal fukka (“to copulate”) or Swedish dialectal focka (“to copulate, strike, push”) and fock (“penis”).
When did fuck enter the English language? To date a word we need to look at early examples that appear in books or other forms of writing. The written form of English fuck is attested to from at least the early 16th century. The early form fukkit dates back to 1503, while an example of the current spelling dates back to 1535. We can assume that fuck is even older than this, but we have an incomplete written record. Fuck is not a word that appears in the kinds of texts that have survived from Middle English or Old English.
British historian Paul Booth recently discovered what he believes to be the earliest known usage of fuck in an English court manuscript that dates back to 1310. The document refers to a gentleman by the name of Roger Fuckebythenavele. This appears to be a legitimate example. However, fuck probably didn’t have the same vulgar meaning it does today. At that time, the equivalent for modern-day fuck was swive. This comes from Old English swifan (“to move lightly over, to sweep”).
Why is the etymology of fuck so shrouded in mystery? It has long been a taboo term and this has made its history difficult to trace. Fuck has been common in speech for centuries but it was deemed so naughty that it was excluded from the very first dictionary, A Dictionary of the English Language, published by Samuel Johnson in 1755. Fuck was also omitted from the first version of the Oxford English Dictionary. In England, fuck was outlawed in print for some time and it didn’t appear in a dictionary until The Penguin Dictionary published a definition in 1966.
The taboo status of fuck is behind many myths about this word that has been offensive for a long time and will probably continue to be so for a long time.