That early spelling of the F word looks distinctly Scandinavian, which lead some experts to believe that the word first originated in Northern Europe. Others posit that it's derived from the Middle English words "fyke" and "fike," or the Low German "ficken," which first meant "to scratch" before becoming a swear word.
Experts have dispelled the popular notion that it came from the phrases “Fornication Under Consent of the King” or "Booked For Unlawful Carnal Knowledge,” because pronouncing abbreviations as words was a phenomenon that only emerged in the 20th century.
Most of us commonly drop the F-bomb in moments of anger — a usage often attributed to a woman named Mary Hamilton, who told a group of people (she was clearly miffed at) to "go and f*ck themselves," back in 1836. As far as the first person to use the word as an adjective, that dubious honor goes to a monk of all people, who, in Cicero’s De Officiis, called his boss a “f*ckin Abbot” — something we can all, no doubt, relate too.
For more on the history of the English language's most infamous word click here.