The first diplomatic crisis which arose after his return to office, though the Prince and the Queen were closely concerned with it, passed off without serious disagreement between the Court and the Minister. For some years past a curious problem had been perplexing the chanceries of Europe. Spain, ever since the time of Napoleon a prey to civil convulsions, had settled down for a short interval to a state of comparative quiet under the rule of Christina, the Queen Mother, and her daughter Isabella, the young Queen. In 1846, the question of Isabella's marriage, which had for long been the subject of diplomatic speculations, suddenly became acute. Various candidates for her hand were proposed--among others, two cousins of her own, another Spanish prince, and Prince Leopold of Saxe-Coburg, a first cousin of Victoria's and Albert's; for different reasons, however, none of these young men seemed altogether satisfactory. Isabella was not yet sixteen; and it might have been supposed that her marriage could be put off for a few years more; but this was considered to be out of the question. "Vous ne savez pas," said a high authority, "ce que c'est que ces princesses espagnoles; elles ont le diable au corps, et on a toujours dit que si nous ne nous hations pas, l'heritier viendrait avant le mari." It might also have been supposed that the young Queen's marriage was a matter to be settled by herself, her mother, and the Spanish Government; but this again was far from being the case. It had become, by one of those periodical reversions to the ways of the eighteenth century, which, it is rumoured, are still not unknown in diplomacy, a question of dominating importance in the foreign policies both of France and England. For several years, Louis Philippe and his Prime Minister Guizot had been privately maturing a very subtle plan. It was the object of the French King to repeat the glorious coup of Louis XIV, and to abolish the Pyrenees by placing one of his grandsons on the throne of Spain. In order to bring this about, he did not venture to suggest that his younger son, the Duc de Montpensier, should marry Isabella; that would have been too obvious a move, which would have raised immediate and insurmountable opposition. He therefore proposed that Isabella should marry her cousin, the Duke of Cadiz, while Montpensier married Isabella's younger sister, the Infanta Fernanda; and pray, what possible objection could there be to that? The wily old King whispered into the chaste ears of Guizot the key to the secret; he had good reason to believe that the Duke of Cadiz was incapable of having children, and therefore the offspring of Fernanda would inherit the Spanish crown. Guizot rubbed his hands, and began at once to set the necessary springs in motion; but, of course, the whole scheme was very soon divulged and understood. The English Government took an extremely serious view of the matter; the balance of power was clearly at stake, and the French intrigue must be frustrated at all hazards. A diplomatic struggle of great intensity followed; and it occasionally appeared that a second War of the Spanish Succession was about to break out. This was avoided, but the consequences of this strange imbroglio were far-reaching and completely different from what any of the parties concerned could have guessed.