Thanne sawe they therinne swich difficultee
By wey of reson, for to speke al playn,
By cause that ther was swich diversitee
Bitwene hir bothe lawes, that they sayn
They trowe that no "Cristen prince wolde fayn
Wedden his child under oure lawe sweete
That us was taught by Mahoun, oure prophete.

– Geoffrey Chaucer

The Canterbury Tales, The Man of Law’s Tale. The Sultan of Syria desires to marry the woman he has fallen in love with but has never seen, Constance, daughter of the Emperor of Rome. But he gets bad news from his advisors, who say that a Christian emperor would never allow his daughter to marry a Muslim. They see the religious and cultural differences between Constance and the Sultan as an insurmountable barrier. Their advice turns out to be right and is foreshadowing of bad things to come from such a marriage.