"melancholy fitts" of insanity were the result of misery
about his wife's infidelity; but, if she could still "draw from him
speeches to her advantage," this cannot have been the case. The
prosecution of Lady Purbeck was pretty clearly at the instigation of
Buckingham and not of Purbeck. There is just a possibility that
Purbeck had refused to proceed against her, and that Buckingham
represented him as mad in order to act in his place, as his brother,
and divorce Lady Purbeck; although such a theory is not supported by
strong evidence. There is, however, this evidence in its support, that
Purbeck acknowledged the boy christened Robert Wright as his own son
some years later.

It is true that, fifty years afterwards, in a petition to the House of
Lords[66] by Lord Denbigh against a claim made by a son of Robert
Wright, it is stated that Lord and Lady Purbeck had not lived together
as man and wife for two years before the birth of Robert Wright; and
that Lord Purbeck "was entrusted in the hands of physicians for the
cure of a melancholy distemper, occasioned by the cruelty and
disorders of his wife." But this claimed absence of two years, or
anything approaching two years, is very questionable, if not very
improbable; and although there is not much doubt as to the real
parentage of Robert Wright, Purbeck may have lived with his wife
sufficiently near the birth of the boy to imagine himself his father.
Indeed, as the following letter will show, she was so far at Court, as
to be living in Prince Charles's house so late as February, 1625, a
year after the birth of the boy. Moreover, as we have seen, Lord
Purbeck held office in Prince Charles's household, and from this it
might be inferred that Purbeck and Lady Purbeck were then together.
This is the more likely because in the following letter Buckingham
expresses a fear that his "brother will be also every day running to
her and give her occasion to worke on him by the subtlty of her
discourse." And if the husband and wife had access to each other when
the proceedings against the latter had gone so far, they are much more
likely to have been together during the year preceding the birth of
the boy.

All this only affects the question whether Purbeck discredited his
wife's fidelity. Nothing has been said above in favour of the theory
that she was faithful.

Buckingham experienced considerable difficulties in the prosecution of
Lady Purbeck. On 15th February, 1625, he wrote[