From Lingo: Around Europe in Sixty Languages, by Gaston Dorren (Atlantic Monthly Press, 2015), Kindle Loc. 737-67:
Two centuries ago, Danish was spoken on four continents in an area twelve times the size of Great Britain. Now, the language is contained in scarcely more than a single country that’s just over half the size of Scotland. Read on for a chronicle of ruin.
The decline began in 1814 when Denmark, a loser in the Napoleonic Wars, was forced to cede part of its territory. All of Norway – many times larger than Denmark proper – suddenly gained independence, albeit initially under the rule of the Swedish king. Danish, having been the official language for centuries, had exerted a strong influence on Norwegian, particularly the kind spoken by the urban elite. Norwegian nationalists now had two objectives: out with the Swedish king, and out with the Danish language. It took a while, but eventually they managed both.
The Danish language was also losing ground further afield. In 1839, school students in the Danish West Indies (yes, they existed) were no longer taught in Danish, but in English instead. In 1845, the Danes sold their Indian trading posts to the United Kingdom, and followed suit in 1850 with their West African colonies. And in 1917 the Danish West Indies were sold off as well, this time to the United States. With that, Denmark was no longer a tropical country. Granted, few people actually spoke Danish in these colonies. But in 1864 the motherland itself also took a hit: in the spoils of war, the region of Slesvig was given to Prussia and renamed Schleswig. To this day, the German province of Schleswig-Holstein is home to a Danish-speaking minority numbering tens of thousands.
Then, in 1918, Danish morale took another blow: after more than five centuries under Danish rule, Iceland gained independence. Admittedly, Danish had never been more than an administrative language, but even this status was now lost. Some time later, Iceland also demoted Danish from its position as the most important foreign language. From then on, young Icelanders would focus on English at school instead.
The Faroe Islands, to the north of Scotland, acquired autonomy within the Danish kingdom in 1948 and promptly declared their native Faroese to be the national language. To help soften the blow, Danish retained its administrative status, but in practice it was used only for official contact with the motherland.
And so all that remained of Denmark’s colonies was the largest and most sparsely populated of them all: Greenland. Until 1979, that is, when the island was granted limited autonomy and permission to govern in its own language, Kalaallisut, otherwise known as Greenlandic. This decision came as no great surprise. Although Danish was a mandatory school subject, many Greenlanders struggled to speak the language, which was poles apart from their own. In autonomous Greenland, Danish initially retained more official functions than in the autonomous Faroe Islands. But that has since changed as well: in 2009, Kalaallisut became the one and only official administrative language. With this move, Greenland achieved a unique position: the only country of the Americas (yes, Greenland is part of the Americas), from Canada all the way down to Chile, where the indigenous language doesn’t play second fiddle to that of its colonial master. The poor Danes. Rejected by the Norwegians, betrayed in the warm-water colonies, defeated in Slesvig, then dumped by the cold-water colonies as well. But the Danes do have one consolation: their ancestors were among those who occupied England in the fifth century and thus laid the foundations for English – a language that has conquered the world like no other.