At one point, public order enforcement in the UK was carried out by the army, who were not above making cavalry charges against peaceful protesters:
https://en.wikipedia.org/wiki/Peterloo_Massacre
That power has been taken away from the army in the UK. It now lies with the police, who, er, well at least they don't have swords:
https://en.wikipedia.org/wiki/Battle_of_Orgreave