Bitwixen Theseus and hym Arcite:
That if so were that Arcite were yfounde
Evere in his lif, by day or nyght, oo stounde
In any contree of this Theseus,
And he were caught, it was acorded thus,
That with a swerd he sholde lese his heed.
Ther nas noon oother remedie ne reed.

– Geoffrey Chaucer

The Canterbury Tales, The Knight’s Tale. After Theseus’s childhood friend Perotheus makes a plea on behalf of Arcite, Theseus agrees to release him from prison. But the strict terms are that Arcite must leave Athens forever and never return. If he is ever caught there again he will lost his head, he is warned.