This interactive diagram shows the number of New Zealand fatal and non-fatal casualties for each month of the Gallipoli campaign (April-December 1915).
By far the worst month was August, when the Sari Bair offensive (including the assault on Chunuk Bair) and attacks on Hill 60 resulted in over a third of New Zealand casualties for the entire campaign.
Note: the statistics used for this graphic are based on casualties reported up to 8 February 1920 in British War Office, Statistics of the Military Effort of the British Empire during the Great War (1922). While it will probably never be possible to get precise casualty figures, recent research suggests that the official record needs some adjustment. According to Richard Stowers, Bloody Gallipoli (2005), the Gallipoli campaign resulted in 2779 New Zealand deaths.
Ministry for Culture and Heritage
