During which years was the First World War fought?
1914 to 1918.
The First World War ran from 1914 to 1918, and Britain fought on the winning side alongside its allies. It's the opening date of a whole run of twentieth-century history facts in this chapter, so getting 1914 to 1918 solid gives you a timeline anchor for everything that follows, right through to the Second World War.
Why it matters: These four years frame every First World War fact that follows.
Memory hook: Fourteen to eighteen. The Great War's scene.
Official handbook: Chapter 3, section 3.4, page 23