Trench Art's most basic definition is: Something made from the debris of war or made to represent something military.  To take this further, according to acknowledged trench art expert Nicholas J. Saunders, trench art is, "Any object made by soldiers, Prisoners of War and civilians, from war material, as long as the object and the maker are associated in time and space with an armed conflict or its consequences." 

The phrase "Trench Art" although catchy is a somewhat inappropriate phrase, implying that it was created in the trenches, which are associated with the First World War. While many pieces were made in the trenches or close by, the majority made during the first World War was not produced in the "Trenches" but in the machine shops or hospitals or in some town miles behind the front lines. The vast majority of what is called trench art was produced between 1919 and 1939 when it became popular to visit the battlefield sites to see where a loved one fought and sometimes died.