The great Irish poet W.B. Yeats, too timid to join the Rising himself, now hymned the fallen rebels as "...All changed, changed utterly...A terrible beauty is born". Yeats was right. The rising changed everything. Politically it led directly to the election of a pro-independence Irish Parliament in 1918, and then to a long, drawn out and bloody guerilla campaign waged by the newly-created IRA which – in contrast to the military failure of 1916 – led eventually to Britain granting independence to the 26 counties of southern Ireland. Albeit posthumously, the men of violence of 1916 had finally triumphed.

What, if any, lessons can we learn from this episode – whose centenary was solemnly commemorated in Ireland this weekend – as we struggle to contend with our own men of violence equally bent on pursuing their ends through a welter of innocent blood in New York, Madrid, Paris, Brussels and, of course, London?

Perhaps the most obvious parallel is the stumbling incompetence 100 years ago of the British authorities which matched, if it did not exceed, the staggering ineptitude of the Belgian "intelligence" services in their woeful failure to anticipate and prevent the outbreak of last week's insensate savagery in Brussels.