In my review of War and Peace I commented on the extraordinary level of dominance that French enjoyed over other European languages during the period described by Tolstoy. The rise of English in the late 20th century would have seemed bizarre to anyone living just a few generations ago.
Britain became a political superpower right after its Industrial Revolution, but that had almost no effect on the prestige or popularity of its language outside of the British Empire's domains. A 100 years ago there seemed to be no reason to expect that America's rise was going to challenge French either. A language's prestige depended on its association with high culture, not with raw political power. This is why Latin could still be taught to millions of schoolchildren 1,500 years after the Roman Empire's fall. For centuries French was the premier European language not because France had a lot of power (sometimes it did and at other times it didn't), but because it had developed an extraordinarily refined culture which people wanted to emulate.
In the final analysis it wasn't England's or even America's political rise that made English prominent, but the precipitous decline of reverence for high culture after WWI. In the 20th century, perhaps for the first time ever, a culture no longer needed to be perceived as refined for foreigners to want to emulate it.
Anyway, to demonstrate just how marginal English seemed to everyone before the 20th century, I'm going to talk about the English Channel. As you probably know, the French call that body of water La Manche (the Sleeve). The Channel was always more important to the English (it connected them to the rest of the civilized world) than to the French, but it's shared by both countries and cultures equally and its naming by other nations can serve as a kind of test of linguistic influence.
If you bring up the English Channel in the Wikipedia and then click on the word "Languages" on the left, you'll see links to the corresponding articles in other tongues. It comes as no surprise that 13 of the 13 living Romance languages and dialects that have their own articles about the English Channel call it La Manche or something similar - after all, French is a Romance language itself. Why wouldn't its sister tongues take its side in this little linguistic dispute?
The fact that only 4 out of the 10 Germanic languages and dialects I looked at follow the English lead in naming the Channel English is far more telling. And one of those 4 is Scots! Germans call the Channel Ärmelkanal. Der Ärmel, just like La Manche, means "the sleeve". Icelandic does the same thing. The Dutch chose to screw their English relatives in a somewhat different manner - they just call it Het Kanaal (the Channel), strategically dropping the English part.
By now you wouldn't be surprised to learn that all 11 Slavic languages I looked at in the Wikipedia call the Channel "La Manche".
Most non-Indo-European languages agree: languages as diverse as Basque, Estonian. Mongolian, Swahili, Turkish, Kurdish, Hungarian, etc., use the name "La Manche" or, more precisely, its local manglings.
The ones that call the Channel English are few and far between, for some reason including Finnish, Malay and Chinese.