[en] The mania for agriculture at the time of the Enlightenment, with the breakthroughs it created in the countryside, has not had the role with which people have sometimes credited it. For the three princes of Monaco who shared this mania it was more than a hobby. While being enlightened enthusiasts they also had a political and social mission: the patronage of the countryside. In Normandy Honoré III (1720-1795) embraced two fashionable fads of the aristocracy at the time – horse breeding and a mania for everything English. The introduction of mulberry trees in Monaco, from the 1730's onwards, was a continuation of the efforts made by the French monarchy to develop within the regions of France a type of agricultural activity that was lucrative; it was also a demonstration of the desire of the princes to make use of the resources of the principality in varied ways. The Duke of Valentinois, who was to be Prince Honoré IV (1758-1819), had a comparatively large number of books on farming, including English works, and this is further confirmation that at the end of the 18th century there was a certain fondness for the subject of land management. Honoré V (1778-1841), who was more practical than scientific, and who had retired to his estates in Lower Normandy at the time of the July monarchy, was opposed to the excesses of liberalism and wanted to revive the ties between the manor and the peasantry: his aim here was to make use of the production surpluses resulting from new crop rotation practices to provide work for, and feed the needy and the beggars. Heralding the agrarian movement of the end of the 19th century, this commitment to a philanthropic method of farming is a testimony to the continuing paternalistic ideal of the country gentleman. While being more of a social, economic or political movement rather than a scientific one, it nevertheless opened up the way to some degree of progress.

[fr] L'agromanie des Lumières n'a sans doute pas eu, dans le progrès aux champs, le rôle qui lui est parfois prêté. Mais, pour les trois princes de Monaco qui participent de cette inclination, elle est, en tout cas, plus qu'un hobby. S'ils sont des amateurs éclairés, ils ont aussi un projet politique et social : le patronage du monde rural. Honoré III (1720-1795) épouse, en Normandie, la double mode aristocratique de l'élevage chevalin et de l'anglomanie. L'implantation du mûrier à Monaco, à partir des années 1730, suit les efforts fournis par la monarchie française pour développer, en ses provinces, cette culture réputée rémunératrice, et manifeste la volonté des princes de diversifier les ressources de la principauté. La possession par le duc de Valentinois, futur Honoré IV (1758-1819), d'un nombre relativement important de livres d'agronomie, y compris d'ouvrages anglais, atteste encore, à la fin du 18e siècle, d'une dilection certaine pour le ménage des champs. Honoré V (1778-1841), quant à lui, plus praticien que savant, retiré sous la Monarchie de juillet sur ses terres de Basse-Normandie, s'oppose aux excès du libéralisme et veut renouer les liens entre château et paysannerie : son objectif est de profiter des surplus de production que permettent les nouveaux assolements pour occuper et nourrir nécessiteux et mendiants. Annonçant l'agrarisme de la fin du 19e siècle, cet investissement agro-philanthropique témoigne de la permanence de l'idéal paternaliste du gentilhomme rural. Plus social, économique ou politique que scientifique, il ouvre néanmoins la voie à des formes de progrès.