The Burden of Power is the fourth volume of Alastair Campbell's diaries, and perhaps the most eagerly awaited given the ground it covers.
It begins on September 11, 2001, a day which immediately wrote itself into the history books, and it ends on the day Campbell leaves Downing Street.
In between there are two wars: first Afghanistan, and then, even more controversially, Iraq.
It was the most difficult decision of Tony Blair's premiership, and almost certainly the most unpopular.
Campbell describes in detail the discussions with President Bush and other world leaders as the steps to war are taken, and delivers a unique account of Blair as war leader.
He records the enormous political difficulties at home, and the sense of crisis that engulfed the government after the suicide of weapons inspector David Kelly. And all the while, Blair continues to struggle with two issues that ran throughout his time in government - fighting for peace in Northern Ireland, and trying to make peace with Gordon Brown. And Campbell continues to struggle balancing the needs of his family with one of the most pressurised roles in politics.
Riveting and revelatory, The Burden of Power is as raw and intimate a portrayal of political life as you are ever likely to read.