This book is not a critical study nor even really a history of Ireland's early nineteenth-century revenue police. It is rather a handbook or guide to the force between about 1830 and its disbandment in 1857. By then the British government believed that the Irish Revenue Police had largely succeeded in their mission of curbing the country's substantial illegal distilling industry.

Illicit distillation had developed during the late-eighteenth century into an important cottage industry in parts of the north and west of Ireland. This was a consequence of rising taxes that had pushed up the price of legal or ‘parliament’ whiskey. From the 1780s, parties of so-called still-hunters were recruited by excise officers and magistrates but help from the army was also considered essential. However, when military aid was withdrawn in 1818, the excise authorities began the appointment of policemen, many of whom were ex-soldiers, and the establishment of stations, first in Connacht and then in parts of Ulster. This revenue force was re-organised, consolidated and given additional powers in 1824, 1830 and 1836. In the latter year, it comprised around 1,050 men in seventy parties headed by a chief inspector, with its headquarters and training depot located in Dublin.

Herlihy's book explains briefly why the revenue police were established and later disbanded; it sketches the force's structure, duties, pay, training and discipline; and it offers advice on sources to readers who may wish to research a revenue policeman ancestor. The book also includes the reminiscences of Waterford-born Matthew Power, who, after serving as an officer in the force between 1847 and 1854, went on to pursue a successful career in English policing. All this material takes up ninety-six pages, with the remaining nearly 150 pages of the book being devoted to a series of appendices. These list the names of the roughly 4,000 men who were members of the force between 1830 and 1857. On disbandment in the latter year, a little over half the 1,100 serving revenue policemen joined either the Irish Constabulary, which continued the task of still-hunting, or the Dublin Metropolitan Police. Herlihy also provides maps showing the distribution of the force and gives the names of the officers in charge of parties, stations and divisions. Donegal was always the most heavily policed county, having eighteen parties of revenue police, followed by Mayo, Tyrone, Sligo, Leitrim and Roscommon, with around thirty parties in total. The force also acquired its own steamer, which cruised the coast from Galway Bay to Lough Foyle, allowing the police to pursue distillers who sometimes took refuge on off-shore islands.

Herlihy demonstrates that revenue policing was a tough job. Chasing well-organised and sometimes armed gangs of distillers, who were very familiar with their local areas, over bogs and mountains in the middle of the night, in all weathers, required a good deal of determination and strength, not to mention courage. Yet constables were poorly paid and subject to harsh discipline; living a spartan life in barracks, they were forbidden from marrying. They were also hated in poor areas where tenant farmers depended upon distilling in order to pay their rents. Nor were they much liked in such areas by struggling landlords either. However, the fact that constables could be rewarded with money for the equipment and whiskey they confiscated and the distillers they arrested undoubtedly encouraged them in the fulfilment of their unpopular duties.

Herlihy has collected and collated a great deal of valuable information. Yet, it is rather a pity that he does not discuss how the revenue police were treated in contemporary fiction because they make some notable appearances in the works of writers like the Banim brothers, Gerald Griffin and William Carleton. Anthony Trollope's first novel, The Macdermots of Ballycloran, written during 1843–5 when Trollope was employed by the post office in Leitrim, a county noted for illicit distilling, revolves around the killing of a deeply unpopular revenue police officer. Although the book was not a success when published in 1847, Trollope always believed that it offered an accurate portrait of Irish rural life on the eve of the Famine. If, in the future, someone decides to undertake a more analytical study of the Irish Revenue Police, there is little doubt that this book will prove an essential resource.