This is something I recently came to think about as I was trying to find a substitute word for "hell" (as in "what the hell is going on?!") in a fantasy world that doesn't have a concept of hell, and I got curious about swear words in fantasy. Often it seems to me that fantasy swear words ends up sounding silly ("by the beard of my ancestors") though. After doing some digging I found out that the words "fuck" and "cunt" have been in use as far back as the 16th century, more interestingly to me though was the word of the use "sard" earlier and I've considered adopting this for my own story, as it's sort of a cool word. Have any of you invented swear words for your fantasy stories and if so, what were they and how did you come up with it?