Chronology of Operations on the Western Front

The following chronology focuses primarily on the fighting on the Western Front between 1914 and 1918, with particular attention paid to the French army's involvement.

Dates	Events	Casualties
1914
28 June	Archduke Franz Ferdinand of Austria assassinated
2 August	Mobilization begins in France
3 August	Germany declares war on France and invades Belgium
5 August	German attack on the fortress of Liège (Belgium)
	Battle of the Frontiers
7-25 August	French offensive in Alsace (Battle of Alsace). Two French offensives by French I Army (7 and 14 August) are replused.
14-25 August	French offensives in Lorraine (Battle of Lorraine) and in the Vosges by French I and II Armies are repulsed. German counter-attack on 20 August. French return to the offensive on 25 August. Stabilization in September.
16 August	End of the Battle of Liège. French V Army marches into Belgium.
20 August	Belgian army withdrawals to Anvers. Bruxelles falls to German army.
22-25 August	French offensive in the Ardennes (Battle of Ardennes) by French III and IV Armies. Battles of Paliseul, Neufchâteau, Betrix, Vitron, Ethe, Rossignol, Pierrepont. French repulsed and driven back.
22-23 August	Battle of Charleroi (Battle of the Sambre), French V Army attacks Germans along the River Sambre and is bloodily repulsed.	22 August is recorded as the bloodiest single day for the French army: 67,000 casualities, including 27,000 killed.
23 August	General withdrawal of French V army. British army (BEF) engages Germans at the Battle of Mons.
24 August	Seige of the Fortress of Maubeuge begins.
26 August	Left flank of BEF folded up by German I Army.
26–30 August	Battle of Tannenberg in East Prussia (Poland). Russian army nearly destroyed.
29 August	Battle of Guise. French V Army counter-attacks pursuing Germans, checking their advance.
30 August	General Joffre gives the order to fall back to the River Seine. The Retreat to the Marne begins.	Total for August: 460,000, incl. 230,000 French
31 August	German I Army (von Kluck) alters his march from his course west-southwest to south-southeast.
	Battles of the Marne and the Aisne
4-10 September	First Battle of the Marne	520,000, incl. 250,000 French (of which 80,000 dead)
4 September	French VI Army attacks the flank of German I Army.
6 September	Counter-attack at the River Marne. General battle on all fronts.
7 September	Battle of Saint-Gond swamps. Fall of Fortress of Maubeuge.
10-13 September	General withdrawal of German army to the River Aisne. Battle of the Ourcq. Germans resist Allied advance.
20-25 September	German offensive on Verdun and in the Woëvre Plain is driven back but salliant forms around Saint-Mihiel.
26 September	French forces check German offensive between the River Oise and the River Meuse.
	Race to the Sea
18-24 September	Battle of Picardy. French II Army transferred from Lorraine to the Somme. Stabilization of the fron to the west of Péronne.
3 October	Creation of the French IX Army, for the defense of Arras.
9 October	Beligan army withdraws to Ostende. BEF takes up positions north of Béthune.
16 October-30 November	Battle of the Yser (Belgium). German IV Army attacks French, Belgian and British forces. Germans prevented from capturing the Channel ports.
27-30 October	The locks around Nieuport (Belgium) are opened, inundating the lower valley of the Yser.
30 October-24 November	German offensive on Ypres and the mounts of Flanders (First Battle of Ypres). French and British forces prevent German capture of Ypres.	Total (Yser and Ypres): 165,000, incl. 50,000 French
6-17 November	Renewed German offensive on Ypres and Dixmude. The front has become locked, from the North Sea to the Swiss border.
16 December-5 January	French attacks in Artois (First Battle of Artois), attempt to capture Notre-Dame de Lorette defeated with heavy losses.
1915
	"Nibbling" Operations
20 December-12 January	"Fight for the observatories": General French attacks all along the line: in Flanders, at La Boiselle, in the Argonne Forest, Butte of Vauquois, on the Meuse, the Aisne, and around Reims.
19 January-26 April	German and French attacks and counter-attacks in the Vosges Mountains, primarily on Hartmannswillerkopf (le Viel-Armand).	30,000, incl. 15,000 French
16 February-18 March	Attacks by the French IV Army in Champagne (First Battle of Champagne) on 8km front between Beauséjour and Bois-Sabot. Advance made of only 1km.	140,000, incl. 93,000 French
17 February-24 May	French and Germans engage in underground mine attacks on the Buttes of Eparges and Vauquois.	French only: 40,000, incl. 5,000 "vanished"
10 March	British assault on Neuve-Chapelle with minimal gains	British only: 12,000
22 April-25 May	Second Battle of Ypres. First use of gas by German army against French forces.
2 May-15 June	Russian Gorlice–Tarnów Offensive in Eastern Prussia (Poland) resulting in collapse of the Russian lines and mass surrenders
8 May-15 July	German attacks in the Argonne. French counter-attack on 14 July	French only: 80,000
	Seeking the "Breakthrough"
9 May-24 June	French offensive in Artois (Second Battle of Artois). French X Army twice attempts to take Vimy Ridge (9-15 May and 16-24 June) but fails.	175,000, incl. 102,000 French
22 September	Preparatory French artillery bombardment begins in Champagne
25 September-6 November	French offensive in Champagne (Second Battle of Champagne). French II and IV Armies attack twice (25-29 September and 6 October).	400,000, incl. 190,000 French (of which 50,000 dead)
25 September-15 October	French offensive in Artois (Third Battle of Artois). French and British attack but make minimal progress.	160,000, incl. 50,000 French
	Dardanelles and Balkans
19 February	Beginning of Dardanelles campaign. Long-range bombardment of the Turkish works at Kum-Kale and Sedd-ul-Bahr.
18 March	Allied naval squadron pushes into the Dardanelles Straits and duels with Turkish batteries. Three warships sunk including the battleship Bouvet.
25 April-October	Allied amphibious assault on the Gallipoli penninsula. Offensive against Krithia and Mount Achi Baba.	500,000, incl. 52,000 French
5 May-7 August	Battle de Krithia - Kereves Dere (Gallipoli). Anglo-French attacks result in minimal gains.
3 October	Creation of the Army of the Orient, intended to support Serbia
8 December	Evacuation of the remaining Allied expeditionary units from the Dardanelles to Salonika.
12 December	Army of the Orient falls back to the entrenched camp of Salonika
1916
	Verdun
21 February-18 December	Battle of Verdun	~710,000, including ~380,000 French (of which 160,000 dead)
21 February	German opening bombardment and assault on the right bank of the River Meuse.
25 February	Fort Douaumont falls. General Pétain assumes command of the Verdun sector.
6 March	German assault on the left bank of the Meuse
9 April-29 May	General German assault on both banks of the Meuse, assault on Mort-Homme
1 May	General Pétain replaces General Langle de Cary as head of the Center Group of Armies, General Nivelle replaces Pétain at Verdun.
4-29 May	German offensive on Hill 304 and Mort-Homme
22 May	French assault (General Mangin) to retake Fort Douaumont fails
7 June	Fort Vaux falls to Germans after 7-day assault
23 June	Germans resume offensive on right bank of the Meuse. Germans take Thiaumont works, from the Fleury to Sainte-Fine Chapel.
11 July	German offensive halted at Fort Souville
1-6 August	Final German offensive on the right bank of the Meuse
24 October	General French offensive (General Mangin) on the right bank of the Meuse. Fort Douaumont is retaken.
2 November	French retake Fort Vaux
15-18 December	Renewed French offensive, retaking of Hardaumont Range and much of the ground lost in February.
	The Somme
24 June	Preparatory Allied artillery bombardment begins along the River Somme
1 July-20 November	Battle of the Somme	~1,200,000, incl. 200,000 French (of which 50,000 dead)
1 July	Allied offensive north of the Somme. French VI Army (General Fayolle) makes good initial progress seizing all first-day objectives (German first line) and many objectives in second line.
10 July	French forces have advanced 10km to outskirts of Péronne, taking 12,000 prisoners, but must halt their advance due to negligible progress by British forces.
14 July	New British offensive along the Somme. In British sector, German second line is finally taken.
18 July	German counter-attack on the Bois Delville
3 September	French VI Army relaunches offensive on 3 September, followed the next day by French X Army (General Micheler)
15 September	British offensive resumes. First use of tanks on the battlefield.
20 September	German counter-attacks are repulsed
October 5	French V and X Armies make final push
20 November	Allied offensive called off
12 December	General Pétain replaces General Joffre as commander-in-chief of the French army.
1917
	Aisne offensive
8 March	Start of the Russian Revolution
15 March	Tsar Nicholas abdicates the throne
16 March	Operation "Albéric": Germans begin withdrawal to Hindenburg Line, between the Somme and the Oise.
6 April	United States declares war on Germany
9-16 April	British attack in Artois. Canadians capture Vimy Ridge.
9-15 April	French III Army assault on Saint-Quentin is checked
16 April-20 May	Chemin-des-Dames "Nivelle" offensive (Second Battle of the Aisne) with large deployment of tanks	350,000, incl. 187,000 French (130,000 by April 25 alone)
29 April	First outbreak of mutiny among French troops. Incidents of mutinies and general insubordination would increase in number in May, topping off in June.
15 May	General Pétain replaces Nivelle as commander of the French Armies of the North and North-East.
	Limited offensives
28 May-7 June	BEF attack and reduction of the Messine salient
25 June	First American troops land in France.
31 July-10 November	Third Battle of Ypres (Passchendaele). British and French (I Army) attacks on Ypres salient fail.
31 July	Beginning of Franco-British offensive in Flanders
20 August-21 September	French offensive at Verdun (main efforts on 20-26 August and 7-8 September)
7 November	Russian "October Revolution" begins
23-26 October	Battle of Malmaison
20-30 November	British offensive on Cambrai with massive deployment of tanks
16 December
1918
	German offensives
21 March-5 April	Operation "Michael": German offensive against the British III and V Armies on the Somme, between Bapaume and Noyon in the direction of Amiens. Intervention of French reserves.
26 March	General Foch appointed as Supreme Allied commander-in-chief
9-30 April	Operation "Georgette": German offensive in Flanders to take Lys. French intervention. Half of the French army positioned north of the River Oise.	French only by 1 May: 340,000
27 May-6 June	Operation "Blücher": German offensive on the River Aisne. Disaster of the French VI Army.
1-26 June 26	American forces engage Germans in Battle of Belleau Wood.	American only: 10,000
9-13 June	Operation "Gneisenau": German offensive agaist the French III Army. Battle of Matz. French counter-attack on 11 June.
15 July-2 August	Opertation "Friedensturm"("Assault for Peace"): German offensive in Champagne (Fourth Battle of Champagne). French IV Army north of Reims resists, V and VI Armies are beaten back. X Army counter-attacks at Viller-Cotterets.	French only for July: 210,000
	Allied counter-attack
8-10 August	Franco-British offensives in Picardie and around Matz.
20 August-3 September	Second phase of releasing offensives. French X Army attacks north of the Aisne. British offensives in Artois and Soissons, withdrawal of German army to Hindenburg Line (20km retreat). The line is reached on 10 September.	French only for August: 170,000
12-16 September	Reduction of Saint-Mihiel sailient by Franco-American offensive
15 September	In Macedonia, rupture of the Bulgarian front by the Army of the East
26-30 September	Allied general offensive against the Hindenburg Line. Meuse-Argonne Offensive: French IV Army and American I Army attacks on a front from Moronvillers to the Meuse.	410,000, incl. 122,000 Americans and 70,000 French. French only for September: 100,000
29 September	Bulgaria signs armistice with Allied powers
October	Army of the East offensive extends in three directions: Constantinople, Roumania, and Hungary.
4-12 October	South of the Oise, French forces push German army back to Hunding Line. North of the Oise, on 8 October Germans begin retreating to Hermann Line.
8 October-November	American forces pushes German army back to Hermann Line, devolves into a general fighting withdrawal.
14-26 October	Allied general offensive against Hermann-Hunding-Brunhild Line. Taking of the Lille-Roubaix-Tourcoing Triangle. The Frontier of the Pays-Bas reached on 20 October. Hermann-Hunding Line taken between the Escaut and the Argonne.	French only for October: 133,000
31 October-November	General push between the Frontier of the Pays-Bas and the River Moselle. An offensive is planned in Lorraine for 14 November.
11 November	The Armistice is signed by Germany
	French total cas.: ~1,500,000 killed, ~3,200,000 wounded