It is the unhappy fate of some once-well-known writers to be completely forgotten; it is the perhaps unhappier fate of others to achieve a certain dubious immortality not through their own work but as "characters" in the anecdotes, memoirs, and fiction of their contemporaries. Such is the case of William Maginn, who is now known, if at all, as what Michael Sadleir termed a "pungent marginal note in the lives of other men" or as the purported original of Capt. Charley Shandon in William Makepeace Thackeray's Pendennis (1848-1850). Yet in his own time Maginn was among the most feared, respected, and influential journalists in England.

William Maginn was born on 10 July 1794 at Marlboro's Fort, Cork, Ireland, to Anne Eccles Maginn, descendant of an old Scottish family, and John Maginn, who ran a private school on Marlboro Street, where, he said, he tried to teach boys to think rather...