"The Troubles" used to refer to the period 1913-1923, but more recently the weight of meaning has moved North; and whereas the former "Troubles" began with the Bachelor's Walk shooting and ended with the Civil War, those in the North of Ireland have lasted three times as long - a sobering fact. Tim Pat Coogan, who already has written lives of Collins and de Valera, here takes up the story from where these crucial histories left off. On the whole, it seems strange that the Stormont regime survived as long as it did, but the fall of Stormont - something which for decades had seemed to republicans as unattainable as storming the Bastille had to French revolutionists of 1780 - has brought no relief either, for the Catholic minority, or for the violence-wracked province in general. Now that Bloody Sunday in Derry has become headlines again, it is salutary to read Coogan's account, which is sober and unemotional and leaves little reasonable room for doubt that the paratroopers - whatever their motives or their "priming" may have been - killed a number of unarmed and innocent people. The murky interim of the 1970s brought in the occult forces of the British Secret Service, and there seems little point at this stage in evading the role of the Littlejohn brothers in the Liberty Hall bombings of 1972. Coogan also investigates the Monaghan and Dublin car-bombings of 1974 and directly implicates Captain Robert Nairac, who was killed (under what circumstances we still do not know) by the IRA a few years later. He examines the background to the ceasefire in which Albert Reynolds played a lead part, but to which the British responded so cautiously, and which was further complicated by the Dublin party politics which brought about Reynolds's downfall. The chessboard of all-Ireland and Anglo-Irish politics has many grey areas as well as the usual neat squares of black and white, a factor which makes this book involuted and densely detailed at times; but it is indispensable reading nonetheless.