faire des châteaux en espagne

This expression is found from the thirteenth century. The explanation that would ascribe it to the followers of the Duc d’Anjou when he became Philippe V. of Spain must therefore be incorrect. The phrases “Châteaux en Asie, en Albanie” were also used, so that it comes to mean “to build castles in foreign countries, where one is not,” and hence “to indulge in illusions.”—Littré , s.v.\n“Chatiaus en Espagne.”—Guillaume de Lorris , Roman de la Rose, l. 2530.\n“De quoi sert-il de bastir des chasteaux en Espagne puisqu’il faut habiter en France?” St. François de Sales, lettre 856.