Any reading recommendations on perceptions of barbarians (especially in France, 19th century) would be greatly appreciated, I'm considering the topic for a masters dissertation.
In Ancien Régime, the division of the estates in the society sometimes associated with their alleged ancestry:
The French Revolution was probably the first opportunity that would reversed such kind of the values attached to each group of peoples:To give an example, Abbé Sieyès (1748-1836) argued that the third estate should be the true nation of the French, descendants of the Gauls who had endured for long under the yoke of foreign invaders, the Romans at first, then the Franks and their descendants [king and the aristocracy]. Thus, it would be the high time to rise and to repel the alien rules, he further called for (Geary 2002: 21).
It was not until the work of Thierry brothers (Augustin and Amédée), and further, Jules Michelet (1798-1874) that gave the Gauls very positive traits (Wood 2013: 102-106). (Added): The modern concept of the nationalism and modern historical science originated in Germany itself flowed into France several times in the 19th century, especially after the defeat of Napoleon and the Franco-Prussian War, so I suppose the re-evaluation of the Gauls as an ancestor of the French nation was also a part of this trend.
In spite of this bipartite division of the Gauls and the Franks and its reverse of the values, however, the latter, especially the baptism of the latter's king, Clovis, has still highly been evaluated as a key moment of the 'birth of French Nation' in the 19th and 20th century, and there have also been abundant of historiographical essays on this topic (though mostly published in French).
In English, the following books (especially those of Geary and Wood) should be introductory works for the topic (also for the 19th century Germany).
References: