THE political, administrative and social consequences of the union of Great Britain and Ireland, and even more the eventual unravelling of the structures it created, have for the greater part of the past century provided Irish historians with a major theme. By contrast the measure itself has received little sustained analysis or discussion. F.R. Bolton's monograph, first published in 1966, remains – more than three decades later – the standard reference. In part this is a tribute to the depth, breadth and penetration of Bolton's account. But there is also at least the suggestion that the negotiation and passage of the union legislation, during 1799–1800, is to be seen as unproblematic, a relatively straightforward event providing a terminus or a starting point for discussion of the more complex and challenging periods on either side.