I know that it used to be an offence that was punishable by torture and death, but I'm wondering when it ceased to be so? England is now close to 40% atheist (or so I've been led to believe) but 600 years ago, those people would have been burned at the stake or dunked in the river or what have you.. just wondering what changed and when. Thank you.
I do not find evidence that atheism was ever a crime in England. (Though atheists faced various forms of discrimination. Shelley (the poet) for example was expelled from Oxford University after publishing a pamphlet called "The Necessity of Atheism".)
Heresy was a crime in England, which might have been used against atheists, but I don't think it ever was. The last execution on the grounds of heresy in England was in 1612, at which time atheism was largely unknown.
(Of course, in the Massachusetts Bay colony, Quakers were executed as heretics as late as 1661).