Charles II, at the National Portrait Gallery, London
During the process that saw him restored to the thrown (he had fled England in 1651 after being defeated by Cromwell at Worcester) Charles issued the Declaration of Breda, part of which reads
And because the passion and uncharitableness (sic) of the times have produced several opinions in religion, by which men are engaged in parties and animosities against each other (which, when they shall hereafter unite in a freedom of conversation, will be composed or better understood), we do declare a liberty to tender consciences, and that no man shall be disquieted or called in question for differences of opinion in matter of religion, which do not disturb the peace of the kingdom; and that we shall be ready to consent to such an Act of Parliament, as, upon mature deliberation, shall be offered to us, for the full granting that indulgence.
Those of "tender consciences" to whom Charles was referring were the many nonconformists that were about to become his subjects. They made up a not-insignificant portion of the population too; in London perhaps as much as 20% of the three-hundred-thousand residents (for how this figure was derived, you'll have to read my paper - ha!).
Charles tried to be as good as his word, but with limited success. Parliament was often at loggerheads with the king, and stymied most of his attempts at enacting legislation that would treat dissenters less harshly. For example, he attempted to issue a "Declaration to Tender Consciences," that would allow him to suspend the penalties for religious nonconformity. Unfortunately, Charles gave Parliament the final word, and it failed to pass the Commons where its members feared it would only increase the number of dissenters (Charles proposed that it was the more draconian laws that had caused a rise in nonconformism, an argument that helped to see his Declaration through the House of Lords).
One of Charles's few victories in religious toleration became the central argument at Lodowick Muggleton's trial. He should have benefited from an Act of Indulgence issued in 1673, but Lord Chief Justice Rainsford, desiring to see Muggleton punished regardless of actual guilt, circumvented that Act by insisting that the evidence at hand had been published after 1673, even though there was nothing to support such a conclusion.