5 January: W.T. Cosgrave returned unopposed as Sinn Féin member of Dublin Corporation.
24 January: Naval battle of Dogger Bank.
18 February: Beginning of German naval blockade of Britain and Ireland.
From Century Ireland: Germany declares Irish sea to be a ‘war zone’.
2 March: Suppression of Arthur Griffith’s newspaper Scissors and paste.
18 March: Amendment to UK Defence of the Realm Act gives non-alien civilians right to claim trial by jury in civil court.
From Century Ireland: What was the Defence of the Realm Act?
21 April: Second Battle of Ypres begins.
From the International encyclopedia of the First World War: The battles of Ypres.
25 April: ANZAC, British, French and Irish troops make first landings on Gallipoli peninsula.
From UCD History Hub: The Irish at Gallipoli.
7 May: Sinking of Lusitania off Old Head of Kinsale with loss of 1,198 lives.
25 May: Wartime coalition cabinet announched; Edward Carson to serve as attorney general; John Redmond excluded at his own request.
29 May: Publication of new series of Workers Republic, printed at Liberty Hall and edited by James Connolly.
19 June: Publication of Nationality, edited by Arthur Griffith.
29 June: Douglas Hyde decides not to continue as president of Gaelic League.
July: 36th (Ulster) Division departs Ireland for England en route to the Western Front.
1 August: Funeral of Jeremiah O’Donovan Rossa, Glasnevin Cemetery, Dublin.
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.
From Century Ireland: Ed Mulhall on planning a Rising for Ireland.
5 October: 10th (Irish) Division begins to arrive in Salonika from Gallipoli to participate in allied campaign in the Balkans.
From History Ireland: Irish soldiers in the Balkans in World War One.
2 November: John Dillon MP and other Irish Party MP’s state opposition to conscription at public meetings across Ireland.
From Century Ireland: Dillon: ‘Ireland will not have conscription’
20 December: ANZAC and British troops withdraw from Gallipoli.
December: 16th (Irish) Division embarks for Western Front.
December: Formation of ‘Military Council’ of IRB: original membership consisted of Seán Mac Diarmada, Thomas J. Clarke, Patrick Pearse, J.M. Plunkett, and Eamonn Ceannt.