STUDENTS of the Union and the Irish and British contexts in which it was shaped owe G.C. Bolton and his study of the subject,The Passing of the Irish Act of Union, a considerable debt. By 1966, the year of its publication, J.C. Beckett, E.M. Johnston and R.B. McDowell had laid the foundations for a re-evaluation of Irish politics and British–Irish relations in the later eighteenth century, but for many aspects of those subjects, including the Union, Lecky's near-eighty-year-old history still remained the principal source. Bolton's was therefore a pioneering book and not only in the sense that it was the first to be based on an exhaustive study of the available evidence: it also broke new ground in its attempt to measure Irish elite and popular opinion on the issue and in the techniques that were used to do so. For these and other reasons, Bolton's study has had a strong influence on more than a generation of undergraduates at Queen's, some of whom have become major historians of the period; his study is, and will remain, an essential guide to the subject.