Also do not compare what Anders did with examples of social reforms in the past century cause there is no analogy. Rather consider any instances of actual social reform taking place peacefully in the Dark Ages.
The 'Dark Ages' is a historiographical concept that has been deprecated. It is pejorative, inaccurate, and nondescriptive. Academic historians do not tend to use it.
But if you're looking for an example of positive social change, largely peaceful, from the medieval era, you could do worse than to look at the emancipation of the peasantry and the end of slavery, both developments that occurred without major violence in post-Roman Western Europe.
Naturally, both of those trends were reversed later; peasants were famously 'bound' again in the ninth and tenth centuries, and forms of slavery emerged again when Western European states began to conquer overseas empires. The trends were also not mirrored in Eastern Europe; much like the Tevinter Imperium of Thedas, the Byzantine Empire was the world's clearing-house for slaves during the same period that slavery had ceased to exist in the West. (Unlike Tevinter, the Byzantines mostly were slave brokers to the Muslim world, and did not employ slave labor themselves in large quantities. But let that go.)
That just goes to show that there is no such thing as an end to history.