The British army during WWI invented some of the most important things during the First World War (tanks, long-range bombers, etc.) and in general had very good equipment (Lee-Enfield, Mills Bomb, Stokes Mortar, etc.) and compared to other factions didn't lose that many men. However, troops from the British commonwealth were deployed to some of the worst places in the history of warfare (Somme, Gallipoli, Passchendaele). The British veterans often recalled the horrors of trench warfare and poison gas, and the war changed the British military command structure and British culture itself in the years to come.