Questio quid juris

Questio quid juris is a Latin law term meaning roughly "I question which law [applies]." Its use dates back to the Middle Ages, and Geoffrey Chaucer, in the Prologue to the Canterbury Tales (c. 1390), has his illiterate "Sumnour" (Summoner, a server of legal writs for the ecclesiastical courts) always shout out the phrase when he is drunk:

And whan that he wel dronken hadde the wyn,

Than wolde he speke no word but Latyn.

A fewe termes hadde he, two or thre,

That he had lerned out of som decree-

No wonder is, he herde it al the day,

And eek ye knowen wel how that a jay

Kan clepen "Watte" as wel as kan the pope.

But whoso koude in oother thyng hym grope,

Thanne hadde he spent al his philosophie;

Ay "Questio quid iuris" wolde he crie.