5 January: W.T. Cosgrave returned unopposed as Sinn Féin member of Dublin Corporation.
24 January: Naval battle of Dogger Bank.
5 April: At the National Volunteers convention at the Mansion House, Dublin, John Redmond praises their response to World War I.
21 April: Second Battle of Ypres begins.
25 April: ANZAC, British, French and Irish troops make first landings on Gallipoli peninsula.
7 May: Sinking of Lusitania off Old Head of Kinsale with loss of 1,198 lives.
25 May: The Prime Minister of the United Kingdom forms the Second Asquith ministry, a national wartime coalition government of twelve Liberals, eight Unionists, including Edward Carson, and one Labour member. In Dublin the Irish Parliamentary Party approves John Redmond's decision not to join.
29 May: Publication of new series of Workers Republic, printed at Liberty Hall and edited by James Connolly.
29 June: Republicans, led by Patrick Pearse, take over the Gaelic League at its Dundalk conference. Douglas Hyde resigns as its President.
1 August: Funeral of Jeremiah O’Donovan Rossa, Glasnevin Cemetery, Dublin. Patrick Pearse gives the oration warning Britain that "Ireland unfree shall never be at peace".
6 August: 10th (Irish) Division lands at Gallipoli.
September: Meeting of new supreme council of Irish Republican Brotherhood (IRB): Denis McCullough (pres.), Sean Mac Diarmada, Thomas J. Clarke, Diarmaid Lynch, Alex McCabe, Dick Connolly, Joseph Gleeson, Patrick McCormick, Patrick McCartan, Patrick Pearse.
20 December: ANZAC and British troops withdraw from Gallipoli.
December: 16th (Irish) Division embarks for Western Front.
December: Formation of ‘Military Council’ of IRB to take control of the plans for a rebellion. The original membership consisted of Seán Mac Diarmada, Thomas J. Clarke, Patrick Pearse, J.M. Plunkett, and Eamonn Ceannt.