Example image of eyePlorer eyePlorer map for 'Battle of Passchendaele': World War I German Empire Triple Entente Passendale West Flanders Ypres Leie North Sea Unrestricted submarine warfare French Army Mutinies (1917) Artillery Canadian Corps Battle of the Lys Attrition warfare Tanks in World War I Douglas Haig, 1st Earl Haig Field Marshal Hubert Gough David Lloyd George Revisionism Harry Patch Eastern Front (World War I) Italian Campaign (World War I) Robert Nivelle Battle of Verdun U-boat Ruhr (river) Battle of the Somme Battle of Arras (1917) Nivelle Offensive Second Battle of the Aisne Philippe Pétain First Battle of Ypres Salients, re-entrants and pockets 4th Army (Germany) Fritz von Lossberg Machine gun Enfilade and defilade Messines Herbert Plumer, 1st Viscount Plumer Counter-battery fire Mining (military) Barrage (artillery) Sulfur mustard Yser Francis Ledwidge Hedd Wyn War poet Fifth Army (United Kingdom) Second Army (United Kingdom)