At the height of his activity Denys Scully (1773- 1830) was regarded by several well-placed observers' including informers employed by Dublin Castle, as the real power in the movement for Catholic Emancipation, behind the rising star of Daniel O'Connell. However, being no orator, by nature inclined towards working behind the scenes, best known to the public for a book on the penal laws that was made obsolete by their repeal, his career cut short by a stroke at the age of fifty, he was already almost forgotten by the time of his early death. With the presentation of his papers to the National Library of Ireland in 1983, after forty years of storage in England. the opportunity has now arisen to reassess his contribution. Augmented by material found in other collections, rearranged in chronological order and supplemented by notes which draw extensively on the official archives as well as other contemporary records, the papers are offered to the public in a volume containing 651 letters and other items.