It is clear from the passage that the spread of nationalism in Europe in the opening years of the 19th century----.

The extension of French as a second or acquired
language is particularly striking. This was to some
extent the result of military and political prestige,
but the virtues of the language itself and French
cultural achievements actually played a much
greater role. The lead which France took in the 12th
century in literature and in other domains made its
language a sort of lingua franca of the cultured
classes of Europe; and in the 17th and 18th
centuries French was cultivated assiduously by the
royal courts and the upper classes of most
European countries and was written by many non-
French authors. But even before the end of the 18th
century French began to lose ground, and the
movement was accelerated by the revival of
national sentiment in Europe at the turn of the
century and later by the rise of English under the
influence of Britain and America. Many things,
however, have found their supreme expression in
French; and its precision, beauty and eloquence
make it a classical language in the true sense of
the word.