From John Mcrae's commanding officer:, Lt. Edward Morrison: "This poem was literally born of fire and blood during the hottest phase of the second battle of Ypres. My headquarters were in a trench on the top of the bank of the Ypres Canal, and John had his dressing station in a hole dug in the foot of the bank. During periods in the battle men who were shot actually rolled down the bank into his dressing station.
Along from us a few hundred yards was the headquarters of a regiment, and many times during the sixteen days of battle, he and I watched them burying their dead whenever there was a lull. Thus the crosses, row on row, grew into a good-sized cemetery.
Just as he describes, we often heard in the mornings the larks singing high in the air, between the crash of the shell and the reports of the guns in the battery just beside us.
I have a letter from him in which he mentions having written the poem to pass away the time between the arrival of batches of wounded, and partly as an experiment with several varieties of poetic metre."