The Old Etonian Mark Sturgis was a senior official in Dublin Castle in the twilight of British rule between July 1920 and January 1922. His lively and engaging diaries - already substantially exploited by scholars such as Charles Townshend - are here published for the first time with a learned introduction and notes from Michael Hopkinson.
It is a valuable resource for understanding Castle politics, but general readers will enjoy Sturgis's accounts of days at the races, long lunches on St Stephen's Green and weekends at Powerscourt. What stands out is the civility of relations between key players of wildly different political positions. How things have changed.
Although he was well connected, it seems Sturgis somehow never penetrated the heart of things. He was a strong supporter of Andy Cope's "peace" policy involving high-risk secret contacts with the Sinn Fein leadership, though Sturgis sometimes felt that Cope made tactical errors. But Sturgis himself never quite got up to speed with the activities of other key players within the system, such as Philip Kerr - an ancestor of Michael Ancram - or the American "superjournalist" Carl Ackerman.
Indeed, despite his access to Lloyd George's mistress, he did not - as Tim Pat Coogan points out in his introduction - fully grasp the scale of the Prime Minister's devious determination to strike a deal with those in Ireland who could "deliver the goods": peace.
There are obvious echoes of contemporary difficulties here. It is intriguing to note the role decommissioning played in delaying the final compromise, then as now. One surprise for many readers will be the central and courageous role played by Sir James Craig, Northern Ireland's first Prime Minister, in orchestrating the final deal with Sinn Fein.
Here Coogan simply misses the point when he speaks of Sturgis having a typical London "mandarin contempt for unionists". Sturgis was no fan of the Ulster Unionists - "the Irreconcilables" as he calls them - but his respect for Craig's policy, closely co-ordinated with Andy Cope, is clear throughout. It is, of course, well known that David Trimble's published historical writings are characterised by a similar admiration for Craig's role.
With the recent conference at Queen's University on the Irish revolution - and indeed Paul Bew's challenge to the conventional wisdom in a recent issue of the Historical Journal - the stale historiography of the period is at last being shaken up.
Steven King is a UUP Special Advisor