For thogh his wyf be cristned never so white,
She shal have nede to wasshe awey the rede,
Thogh she a font-ful water with hire lede.

– Geoffrey Chaucer

The Canterbury Tales, The Man of Law’s Tale. The Sultan may be converting to Christianity, but his mother the Sultaness plans to convert his wedding feast into a bloodbath, as she and her followers get set to massacre the Christians.