A native of Guelph, Ontario, and a veteran of the South African War (1899-1902), John McCrae began the First World War as a surgeon attached to the 1st Brigade, Canadian Field Artillery, 1st Canadian Division. After undergoing a baptism by fire at Neuve Chapelle, France, in March 1915, the Canadians moved to Flanders in mid-April, taking up position in the salient around the Belgian town of Ypres.
On April 22-23, in their first major battle, they distinguished themselves by holding out against the first German gas attack of the war while others around them fled. John McCrae was the officer in charge of a medical aid post in a dugout cut into the bank of the Yser canal, a few miles to the northeast of Ypres. Here, on May 2, McCrae's good friend, 22-year old Lieutenant Alexis Helmer of Ottawa, was blown apart by enemy artillery fire. With the parts of Helmer's body collected in a blanket, McCrae himself read the funeral service.
The next day, McCrae, who had been publishing poetry for many years, completed In Flanders Fields. Eyewitness accounts vary in detail, but agree that he worked on the poem while sitting on the back step of an ambulance near his medical aid post. In the field around him crosses marked the graves of dead soldiers, including those of Helmer and other Canadians killed the previous day. Accounts also agree that poppies grew in the area at the time and McCrae's own notes refer to birds singing despite the noise of battle.