A Trench map shows the trenches of the Great War, 1914–1918. Whilst all of the belligerents made or used maps of the trenches, this article refers mainly to those produced by the British Army. For much of the Great War, trench warfare was almost static, giving rise to the need for detailed large scale maps for both attack and defence. Initially, British trench maps showed the German trench systems in detail but only the British Front line. Later in the war, more and more of the British trenches were shown. The only maps that showed full detail of both sides were the secret editions, usually marked "Not to be taken beyond Brigade HQ" for fear of them falling into enemy hands.