Valiant Hearts: The Western Front

Freddie's first chapter is the Battle of the Marne: he cuts the German barbed wire, blows a fortified bridge and storms the house where his enemy, Baron von Dorf, has his headquarters, only to watch the baron escape by zeppelin. In September 1914 the retreating French and British armies turned on the Germans east of Paris and stopped them, ending hopes of a quick war. A 35-metre monument on the hill of Mondement, one of the battle's hardest-fought positions, commemorates the victory.

Location precision: The game's battle has no exact location; the pin marks the national Marne monument at Mondement.

Visitor guidance: The Mondement monument stands in open country south of Épernay, with views over the marshes of Saint-Gond.

Baron von Dorf's weapon of choice is chlorine gas, and the heroes run into it near Ypres, where Freddie and Emile first team up with Anna. It happened here: on 22 April 1915 the German army opened about 170 tonnes of chlorine on a six-kilometre front north of the town, the first large gas attack in history, and French colonial and Canadian troops took the brunt of it. Ypres itself was shelled to rubble and rebuilt after the war. The Menin Gate lists more than 54,000 Commonwealth soldiers lost in the salient with no known grave.

Location precision: The gas attack was north of the town; the pin marks the Menin Gate memorial in Ypres.

Visitor guidance: Buglers sound the Last Post under the Menin Gate every evening at 8 pm.

The three heroes chase von Dorf's zeppelin all the way from Ypres to Reims, where it comes down in flames; the baron escapes by plane with Anna's father, and Karl, aboard the airship, survives as a prisoner. Reims spent most of the war within range of German guns. Its cathedral, where French kings were crowned, was set on fire on 19 September 1914 when shells hit the timber roof, and became a worldwide symbol of the war's destruction. Rebuilt with Rockefeller Foundation money, it reopened in 1938.

Location precision: The crash is fictional; the pin marks Reims Cathedral.

Visitor guidance: Statues damaged in the 1914 fire, among them the original smiling angel, are kept in the Palace of Tau next to the cathedral.

At Verdun, Emile and Freddie assault Fort Douaumont, where von Dorf is hiding his newest machine, a huge armoured tank, and free Anna's father. The real fort was the biggest of the ring around Verdun. On 25 February 1916, three days into the battle, a small German raiding party walked in almost unopposed through an open window by the moat; its loss shocked France. The French took it back only on 24 October 1916, after eight months of fighting. The concrete fort, scarred by shells, still sits on its hill above Verdun.

Visitor guidance: The fort's galleries are open to visitors; the Douaumont Ossuary and the Verdun Memorial museum are nearby.

One chapter takes the heroes underground at Vauquois, where the war was fought in tunnels as much as in trenches. In 1914 the Germans turned the hilltop village into a fortress, and after failed French assaults in early 1915 both sides started digging. Around 23 kilometres of galleries reached down to 100 metres, and more than 500 mine explosions wiped out the village; in May 1916 one German mine killed 108 French soldiers. The summit is now about 15 metres lower than in 1914, a line of giant craters.

Visitor guidance: The craters are open to walk around; volunteers guide visits into the tunnels on the first Sunday of each month.

Freddie finally corners von Dorf during the Battle of the Somme and beats him in a fist fight on top of his wrecked tank, but spares his life. Tanks really did make their debut on the Somme, on 15 September 1916 at Flers–Courcelette. The battle, from July to November 1916, cost more than a million men killed or wounded on both sides. Above Thiepval, Lutyens's great brick arch, the Memorial to the Missing of the Somme, bears the names of 72,337 British and South African soldiers with no known grave.

Location precision: The game's tank fight has no exact place; the pin marks the Thiepval Memorial.

Visitor guidance: A visitor centre beside the Thiepval Memorial explains the battle; many smaller cemeteries lie along the old front line.

Escaping from a French prison camp because his son is ill, Karl makes his way home to the family farm at Saint-Mihiel, behind German lines, where he finds it gassed and gives Marie his own mask. Saint-Mihiel was in German hands from autumn 1914, at the tip of a salient that cut into the French front. It was freed only on 12–16 September 1918, in the first large offensive led by the American army, the force whose arrival ends the game.

Location precision: Karl's farm is fictional; the pin marks the town of Saint-Mihiel.

The game ends on the Chemin des Dames ridge, in General Nivelle's offensive of April 1917. Ordered again and again into the guns, Emile strikes his officer with a shovel, kills him by accident and is shot by firing squad. Nivelle had promised a breakthrough in 48 hours; its failure set off mutinies in almost half the French infantry divisions, which refused to attack. Pétain, his successor, held about 3,400 courts-martial; 554 men were sentenced to death and 26 executed.

Location precision: Emile's execution is fictional; the pin marks the Caverne du Dragon museum on the ridge.

Visitor guidance: The Caverne du Dragon, an old quarry fought over from below ground, is now the Chemin des Dames museum.