Question

examples in history where a conquered group of people had their language taken away from them or had a language imposed on them?

Answer 1

Colonisation or colonial exploration of North America,South America,Australia,Africa,etc...,

Answer 2

In History, Belgium has a variety of languages like French, Dutch, and Germany. But the people's were forced to speak Only French.

Another example, Srilanka had a variety of  linguists like Sinhalas(74%) , Tamils(18%).
But the peoples were forced to stop speaking Tamil and only speak Sinhala...