Houssaie observes, "The English council were against it, but king James
obstinately resolved on it; being over-persuaded by Gondomar, the
Spanish ambassador, whose facetious humour and lively repartees greatly
delighted him. Gondomar persuaded him that the presence of the prince
would not fail of accomplishing this union, and also the restitution of
the electorate to his son-in-law the palatine. Add to this, the Earl of
Bristol, the English ambassador-extraordinary at the court of Madrid,
finding it his interest, wrote repeatedly to his majesty that the
success was certain if the prince came there, for that the Infanta would
be charmed with his personal appearance and polished manners. It was
thus that James, seduced by these two ambassadors, and by his parental
affection for both his children, permitted the Prince of Wales to travel
into Spain." This account differs from Clarendon.

Wicquefort says, "that James in all this was the dupe of Gondomar, who
well knew the impossibility of this marriage, which was alike inimical
to the interests of politics and the Inquisition. For a long time he
amused his majesty with hopes, and even got money for the household
expenses of the future queen. He acted his part so well, that the King
of Spain recompensed the knave, on his return, with a seat in the
council of state." There is preserved in the British Museum a
considerable series of letters which passed between James I. and the
Duke of Buckingham and Charles, during their residence in Spain.

I shall glean some further particulars concerning this mysterious affair
from two English contemporaries, Howel and Wilson, who wrote from their
own observations. Howel had been employed in this projected match, and
resided during its negotiation at Madrid.