Lord Castlereagh's arrival at head-quarters strengthened the unity of the alliance and enabled them to form some resolutions for the general benefit, and also to decide upon the plan of the political campaign about to be commenced against Buonaparte. England had never recognised the Emperor of the French, and in all the acts of parliament, as well as those of the cabinet, he had no other designation than that of _the common enemy_, or _the head of the government_, a circumstance which facilitated Pozzo di Borgo's labours with Lord Castlereagh towards gaining the object he had in view, viz., the complete overthrow of Napoleon. The English minister, who was armed with full powers, laid down as the fundamental principle of all their diplomatic transactions, that France, although necessary to the balance of power in Europe, must be reduced within her ancient territorial limits, a principle which almost inevitably involved the restoration of the ancient dynasty. This, however, was only mentioned in the acts, both public and secret, of the congress, as a _possibility_ reserved for a further consideration of the French question. One of the most important principles laid down in the political plan of the alliance was the separation of the question concerning Napoleon from those regarding the interests of France. This line of conduct was recommended by Bernadotte, Pozzo di Borgo, and the patriot party, who were the enemies of the emperor, and it was formally announced in the public acts of Frankfort and the proclamations of all the allied troops who crossed the Rhine. Their great object was to weaken the common enemy, at the same time that they promised France that her ancient territory should remain untouched, and hinted at the possibility of establishing a constitution independent of the emperor. By adopting this plan they summoned all disaffected persons to the assistance of the coalition; and, without entering into engagements with any one party, they offered to _all_ the hope of bringing their pretensions and wishes to a favourable issue; they even contrived to conciliate the partisans of a republican form of government as well as the advocates of the regency of Maria Louisa.