Don't know any pre 1500 curses, but I like Shakespeare's "The Devil damn thee black thou cream faced loon...I thouest thou, yea I thouest thou.." (using the familar "thou" to a superior when "you" should have been used was a form of great disrespect, still can be in outdated artifically hidebound languages like French ..

Also I like the Regency curse "Stap me vittles" (stab me vitals)

Also "Rantallion" a man whose penis hangs lower than his scrotum according to the Penguin book of Historical Slang and "fartleberry" for what we call "dags" in New Zealand from Mrs Byrnes Dictionary.