Around Mar 1673 the Test Act was a law enacted by Parliament that required public servants to take an oath according to the rites of the English church and to deny the Catholic doctrine of transubstantiation. The Act undermined the 1672 Declaration of Indulgence.

Evelyn's Diary. 26 Apr 1673. Dr. Lamplugh (age 58) preached at St. Martin's [Map] the Holy Sacrament following, which I partook of, upon obligation of the late Act of Parliament, enjoining everybody in office, civil or military, under penalty of £500, to receive it within one month before two authentic witnesses; being engrossed on parchment, to be afterward produced in the Court of Chancery, or some other Court of Record; which I did at the Chancery bar, as being one of the Council of Plantations and Trade; taking then also the oath of allegiance and supremacy, signing the clause in the said Act against Transubstantiation.

Evelyn's Diary. 19 Jun 1673. Congratulated the new Lord Treasurer, Sir Thomas Osborne (age 41), a gentleman with whom I had been intimately acquainted at Paris, and who was every day at my father-in-law's (age 68) house and table there; on which account I was too confident of succeeding in his favor, as I had done in his predecessor's; but such a friend shall I never find, and I neglected my time, far from believing that my Lord Clifford (age 42) would have so rashly laid down his staff, as he did, to the amazement of all the world, when it came to the test of his receiving the Communion, which I am confident he forbore more from some promise he had entered into to gratify the Duke, than from any prejudice to the Protestant religion, though I found him wavering a pretty while.

Evelyn's Diary. 25 Jul 1673. I went to Tunbridge Wells, Kent [Map], to visit my Lord Clifford (age 42), late Lord Treasurer, who was there to divert his mind more than his body; it was believed that he had so engaged himself to the Duke (age 39), that rather than take the Test, without which he was not capable of holding any office, he would resign that great and honorable station. This, I am confident, grieved him to the heart, and at last broke it; for, though he carried with him music, and people to divert him, and, when I came to see him, lodged me in his own apartment, and would not let me go from him, I found he was struggling in his mind; and being of a rough and ambitious nature, he could not long brook the necessity he had brought on himself, of submission to this conjuncture. Besides, he saw the Dutch war, which was made much by his advice, as well as the shutting up of the Exchequer, very unprosperous. These things his high spirit could not support. Having stayed here two or three days, I obtained leave of my Lord to return.