More or less the same thing happened in France in the last half of the XIXth century : the governments decided that French was the only language to be spoken in the country and, for example, children were severely punished at school if they spoke the local dialect. Yet regional languages resisted, even if they were now spoken by much fewer people. Nowadays, they're freely taught, sometimes even in public schools and, though there aren't many people that currently speak them, their number slightly increases each year.
