European tradition of mixing languages

Mixing languages, of course, is not new.  In fact, it is very old.  Here is a passage from Transforming the Center, Eroding the Margins:  Essays on Ethnic and Cultural Boundaries in German-Speaking Countries (1998), by Dagmar C. G. Lorez and Renate Posthofen (p. 258):

“Genthe describes the long European tradition of mixing languages within literary texts.  While making verses, he tells, some Roman poets already made no difference between Greek and Latin, thereby witnessing the incorporation of Greek culture into Roman culture.  Finally, since the eve of the Middle Ages and throughout the sixteenth and seventeenth centuries, several writers – including Molière in his Le Malade Imaginaire (1673, translated as The Hypochondriack, 1732) – elaborately assimilated their native language to the scholars’ Latin idiom.  This species of poetry is called macaronic because it was inaugurated by Tifi degli Odasi’s Maccharonea in 1490.”

I find it interesting that the mixing of languages is thought to be also a mixing of cultures.  This is a rather big jump from language to culture, but since each language theoretically embodies a particular culture, it is an avenue worth pursuing.  Perhaps the labeling of English as an "international language" would then be problematized, because the language (in theory anyway, even if it has not yet been shown in practice) carries the culture of Britain (and today, of the United States).  The Australian attempt to make English english, or the Indian attempt to make English Englishes, may be masking the hegemonic or imperial nature of the English language.  Perhaps (a thought at this point, without any theoretical basis yet) the widespread use of the English language is threatening not just other languages but entire cultures.