One senses the nation leaning nervously into a particularly awkward series of centenary commemorations. The 1916 anniversary went well. The first World War memorials were tasteful. But the War of Independence and particularly the Civil War offer greater challenges. Those dilemmas are acknowledged in this fascinating documentary from the experienced Nuala O’Connor.

The picture’s unpromising starting point is a dive into the Irish military service pensions archive and a consideration of how payments were made, who gained and who lost out. Around that fulcrum the documentary bends a comprehensive examination of the challenges that accompany commemoration.

The historian Diarmaid Ferriter, who conceived the piece, adds his measured voice to those teasing out important questions that have been little considered in public forums. For all the tales of bravery and resistance, too many combatants have felt their sacrifices and their suffering went unrecognised. There was, in the early days of the State, little understanding of the long-term impact of violent combat.

Though Keepers of the Flame does not absolutely demand big-screen presentation, it profits from some top-quality technical work. Mary Black, Aiden Gillen, Joseph O'Connor and Olivia O'Leary are among those reading the contemporaneous transcripts. Colm Hogan's cinematography balances the talking heads with rich landscapes and washing waves.

Most importantly, the reasonable, humane arguments are structured with the clarity you would expect from a professional historian. It is, in the age of online fury, refreshing to hear contentious issues pondered in such measures tones. An education.

Opens December 14th