The unpleasantness of trench warfare is well known. My understanding is that it was much worse than what they show on Downton Abbey. In the beginning when the troops went over the top of the trenches to attack the enemy the British forces still kept to the old model of marching in perfectly disciplined formation. Effective against the French at Waterloo, maybe, but against German machine guns not so much. The 'three on a match' superstition arose in the trenches; by the time the third soldier got his cigarette lit the German snipers had a bead on him.
Most folks who have spent any time on a battlefield are reluctant to talk about it afterwards. Nevertheless Granddaddy told a story to my mother, who told it to me.
My grandfather and a fellow officer, a close friend, were occupying a trench together. It was springtime. The friend was moved to climb out and roam the countryside, which was somehow possible just then. He found a rosebush, or a number of them, all in bloom. He cut the roses and brought them back to the trench with him. It was a moment of beauty, a rare thing in that time and place.
Suddenly a shell came screaming into the trench and my grandfather's friend was killed. There he lay surrounded by roses. It was an image that my grandfather carried in his memory to the end of his life.
Were they in Picardy? I don't know. It would take me a month to research it. Anyway here's the famous song of that era.