The journals of the reigns of George IV and William IV, extending from 1817 to 1837, were published in obedience to his directions almost ten years after his death. Few publications have been received with greater interest by the public; five large editions were sold in little more than a year, and the demand in America was as great as in England. These journals were regarded as a faithful record of the impressions made on the mind of a competent observer, at the time, by the events he witnessed and the persons with whom he associated. Greville did not stoop to collect or record private scandal. His object appears to have been to leave behind him some of the materials of history, by which the men and actions of his own time would be judged. He records not so much public events as the private causes which led to them; and perhaps no English memoir-writer has left behind him a more valuable contribution to the history of the 19th century. Greville published anonymously, in 1845, a volume on the "Past and Present Policy of England in Ireland", in which he advocated the payment of the Roman Catholic clergy; and he was also the author of several pamphlets on the events of his day.