He was active against Roman Catholics during the alleged Popish Plot 1678-1679 and was removed from the commission of the peace in April 1680 for his overzealousness.
[3] Waller distinguished himself during the period of the Popish Plot by his activity as a Middlesex justice in catching priests, burning Roman Catholic books and vestments, and getting up evidence.
[4] He was elected as a Fellow of the Royal Society in 1679,[5] and early 1680 he was the discoverer of the meal-tub plot and one of the witnesses against Edward Fitzharris.
[8] In 1683 and the following year he was at Bremen, of which place Lord Preston, the English ambassador at Paris, describes him as governor.
Other political exiles gathered round him, and it became the nest of all the persons accused of the last conspiracy, i.e. the Rye House Plot.