par excellence

mid-14c., "superiority, greatness, distinction" in anything, from Old French excellence, from Latin excellentia "superiority, excellence," from excellentem (nominative excellens) "towering, distinguished, superior," present participle of excellere "surpass, be superior; to rise, be eminent," from ex "out from" (see ex-) + -cellere "rise high, tower," related to celsus "high, lofty, great," from PIE root *kel- (2) "to be prominent; hill." From late 14c. as "mark or trait of superiority, that in which something or someone excels."

"through, by means of," 1580s (earlier in various Latin and French phrases, in the latter often par), from Latin per "through, during, by means of, on account of, as in," from PIE root *per- (1) "forward," hence "through, in front of, before, first, chief, toward, near, around, against."