[3] Ancillon took rank among the most famous historians of his day by his next work, Tableau des révolutions du système politique de l'Europe depuis le XVe siècle (1803, 4 volumes), which gained him the praise of the Institute of France, and admission to the Military Academy of Berlin.

Its "sugary optimism, unctuous phraseology and pulpit logic" appealed, however, to the reviving pietism of the age succeeding the Revolution, and these qualities, as well as his eloquence as a preacher, brought Ancillon to the notice of the court.

[3] In October 1814, when his pupil came of age, Ancillon was included by Karl August von Hardenberg in the ministry, as privy councillor of legation in the department of foreign affairs, with a view to utilizing his supposed gifts as a philosophical historian in the preparation of the projected Prussian constitution.

He covered his defection from Hardenberg's liberal constitutionalism by a series of "philosophical" treatises on the nature of the state and of man, and became the soul of the reactionary movement at the Berlin court, and the faithful henchman of Klemens von Metternich in the general politics of Germany and of Europe.

In his chief's most important work, the establishment of the Prussian Zollverein, Ancillon had no share, while the entirely subordinate role played by Prussia in Europe during this period, together with the personal part taken by the sovereign in the various congresses, gave him little scope for the display of any diplomatic talents he may have possessed.

"[4] In May 1831 Ancillon was made an active privy councillor, was appointed chief of the department for the principality of Neuchâtel, in July became secretary of state for foreign affairs, and in the spring of 1832, on Bernstorff's retirement, succeeded him as head of the ministry.

Ancillon therefore rejects both the radical Enlightenment, which he holds responsible for the French Revolution, and mere romanticism, which he denies the ability of a practical state construction that opens up developmental opportunities for people.