This thread also posed the question of whether Mr. Knightley and Emma could properly marry, and the answer is, of course, yes - they were not blood relations. However, in some parts of Europe (pre-Reformation) this would not necessarily have been so. Marriages were forbidden, not only between various forms of blood relation, but between those regarded as closely spiritually related - prohibitions might extend to godfathers and godmothers, and even beyond. In some areas, this became so bad that people wishing to marry could find no-one in their area whom they could properly marry, and would have to try to find a partner in another area. And come to think of it, there is a close spiritual relationship between Mr. Knightley and Emma, which has always made me just faintly uneasy about their marriage.