The medieval canon law of affinity as an impediment to marriage
combined a large range of prohibited degrees with a wide power
of dispensation. After the Reformation, however, English law, in
line with mainstream Protestant opinion, prohibited marriages within the
degrees mentioned in Leviticus, with no provision for dispensation. The
prohibited degrees were set out in ‘Archbishop Parker's Table’
in the
Prayer Book, beginning with the memorable declaration that ‘A man
may not marry his grandmother’. In the nineteenth century, however,
some of these restrictions came to be challenged. The classic case was
that of marriage with a deceased wife's sister, and it was under this
title
that successive bills were introduced to alter the law.
Until 1857 the law of marriage was administered by the ecclesiastical
courts, according to the canon law. However, the civil courts modified
and controlled this canon law by means of the writ of prohibition: canon
law was now subordinate to common law, and where the two conflicted
the civil courts would over-rule the ecclesiastical courts. Marriage with
a
deceased wife's sister was illegal, and, as with other impediments
to
marriage, a case could be brought in the ecclesiastical courts to have
such
a marriage declared void. A case on these grounds could only be brought
during the lifetime of both spouses. Nevertheless, the marriage had
theoretically been void ab initio, and even after one spouse had
died the
survivor could still be proceeded against for incest.