noun Plural exordia, Plural exordiums
The beginning or introductory part, especially of a discourse or treatise.
Late 16th century: from Latin, from exordiri ‘begin’, from ex- ‘out, from’ + ordiri ‘begin’.
“In the beginning, God created…”
“It was a dark and stormy night…”
“When Augustus came out on the porch the blue pigs were eating a rattlesnake—not a very big one…”
“A long time ago in a galaxy far, far away….”
Of course, there are more, but the ones quoted are well known, except, perhaps the one from Larry McMurtry’s Lonesome Dove which is quoted above. That opening line, my memory says, most hooked me as I started reading the novel. I was never more certain that I would enjoy the long book ahead of me.
The rest of the opening lines are probably better known, with some very much overused in stories written by aspiring primary school authors.