| June 28. | Murder of Archduke Francis Ferdinand at Serajevo. |
| July 23. | Austro-Hungarian ultimatum to Serbia. |
| July 28. | Austria-Hungary declares war on Serbia. |
| July 31. | German ultimatums to Russia and France. |
| Aug. 1. | Germany declares war on Russia and invades Luxemburg. |
| Aug. 2. | German ultimatum to Belgium, demanding a free passage for her troops across Belgium. |
| Aug. 3. | Germany declares war on France. |
| Aug. 4. | Germans enter Belgium. |
| Aug. 4. | Great Britain declares war on Germany. |
| Aug. 4. | President Wilson proclaims neutrality of United States. |
| Aug. 6. | Austria-Hungary declares war on Russia. |
| Aug. 7. | Liége occupied. |
| Aug. 10. | France and Great Britain declare war on Austria-Hungary. |
| Aug. 16. | British expeditionary force landed in France. |
| Aug. 18. | Russia invades East Prussia. |
| Aug. 20. | Brussels entered by Germans. |
| Aug. 21-23. | Battle of Mons-Charleroi. Dogged retreat of French and British in the face of the German invasion. |
| Aug. 23. | Japan declares war on Germany. |
| Aug. 23. | Kiaochow in China bombarded by Japanese. |
| Aug. 24. | Fall of Namur. |
| Aug. 25. | Fall and destruction of Louvain. |
| Aug. 25-Dec. 15. | Russians overrun Galicia. Lemberg taken (Sept. 2); Przemysl besieged (Sept. 16 to Oct. 15,and again after Nov. 12). Dec. 4. Russians 3 ½ miles from Cracow. |
| Aug. 26. | Allies conquer Togo, in Africa. |
| Aug. 26-31. | Russians defeated in battle of Tannenberg. |
| Aug. 28. | British naval victory off Helgoland Bight, in North Sea. |
| Sept. 5. | Great Britain, France, and Russia sign a treaty not to make peace separately. |
| Sept. 6-10. | First battle of the Marne. |
| Sept. 7. | Extreme point of German advance. |
| Sept. 7. | Germans take Maubeuge, in northern France. |
| Sept. 11. | Australians take German New Guinea, and other German Pacific island possessions. |
| Sept. 12-17. | Battle of the Aisne. |
| Sept. 16. | Russians driven from East Prussia. |
| Sept. 22. | Three British armored cruisers sunk by a submarine. |
| Sept. 27. | Successful invasion of German Southwest Africa. by General Botha. |
| Oct. 9. | Germans occupy Antwerp, the chief port of Belgium. |
| Oct. 13. | Belgian government retires to Havre, which remains its seat during the war. |
| Oct. 16-28. | Battle of the Ysre. Belgians and French halt German advance. |
| Oct. 17-Nov. 15. | Battle of Flanders, near Ypres, saving Channel ports. |
| Oct. 20-27. | German armies driven back in Poland. |
| Oct. 28-Dec. 5. | De Wet's rebellion in British South Africa. |
| Nov. 1. | German naval victory off the coast of Chile. |
| Nov. 3-5. | Russia, France, and Great Britain declare war on Turkey. |
| Nov. 7. | Kiaochow captured by the Japanese and British. |
| Nov. 10-Dec. 14. | Austrian invasion of Serbia. |
| Nov. 10. | German cruiser Enulen destroyed in Indian Ocean. |
| Nov. 21. | Basra, on Persian Gulf, occupied by British. |
| Dec. 8. | British naval victory off the Falkland Islands. |
| Dec. 16. | German warships bombard towns on east coast of England. |
| Dec. 17. | Egypt proclaimed a British protectorate, under a sultan. |
| Dec. 24. | First German air raid on England. |
| Jan. 1-Feb. 15. | Russians attempt to cross the Carpathians. |
| Jan. 24. | Naval skirmish off Dogger Bank, in North Sea. |
| Jan. 25Feb. 12. | Russians again invade East Prussia, but are defeated in the battle of the Masurian Lakes. |
| Jan. 28. | American merchantman William P. Frye sunk by German cruiser. |
| Feb. 4. | Germany's proclamation of "war zone" around the British Isles after Feb. 18. |
| Feb. 10. | United States note holding German government to a \"strict accountability\" for destruction of American lives or vessels. |
| Feb. 19. | Anglo-French squadron bombards Dardanelles forts. |
| Mar. 1. | Announcement of British blockade of Germany. |
| Mar. 10. | British capture Neuve Chapelle, in northern France. |
| Mar. 17. | Russians capture Przemysl, in Galicia. |
| Apr. 17—May 17. | Battle of Ypres. First use of poison gas. |
| Apr. 25. | Allied troops land on the Gallipoli peninsula. |
| Apr. 30. | Germans invade the Baltic provinces of Russia. |
| May 1. | American steamship Oulf light sunk by German submarine; two American lost. |
| May 2. | Battle of the Dunajec. Russians defeated by the Germans and Austrians and forced to retire from the Carpathians. |
| May 7. | British liner Lusilania sunk by German submarine (1134 lives lost, 114 being Americans). |
| May 9-June. | Battle of Artois, or Festubert (in France, north of Arras). Small gains by the Allies. |
| May 13. | American note protests against submarine policy culminating in the sinking of the husitania. Other notes June 9, July 21; German replies, May 28, July 8, Sept. 1. |
| May 23. | Italy declares war on Austria-Hungary. |
| May 25. | American steamship Nebraskan attacked by submarine. |
| June 3. | Przemysl retaken by Germans and Austrians. |
| June 9. | Monfalcone occupied by Italians. |
| June 22. | The Austro-Germans recapture Lemberg, in Galicia. |
| July 2. | Naval action between Russians and Germans in the Baltic. July 15. Conquest of German Southwest. Africa completed. |
| July 14—Sept. 18. | German conquest of Russian Poland ; capture of Warsaw (Aug. 4), Kovno (Aug. 17), Brest-Litovsk (Aug. 25), Vilna (Sept. 18). |
| Aug. 19. | British liner Arable sunk by submarines (44 victims, 2 Americans). |
| Aug. 21. | Italy declares war on Turkey. |
| Sept. 1. | The German ambassador, von Bernstorff, gives assurance that German submarines will sink no more liners without warning. |
| Sept. 8. | United States demands recall of Austro-Hungarian ambassador, Dr. Dumba. |
| Sept. 25-Oct. | French offensive in Champagne fails to break through German lines. |
| Sept. 27. | Small British progress at Loos, near Lens. |
| Oct. 4. | Russian ultimatum to Bulgaria. |
| Oct. 5. | Allied forces land at Saloniki at the invitation of the Greek government. |
| Oct. 5. | German government regrets and disavows sinking of_ Arabic and is prepared to pay indemnities. |
| Oct. 6—Dec. 2. | Austro-German-Bulgarian conquest of Serbia; fall of Bel-grade (Oct. 9), Nish (Nov. 1), Monastir (Dec. 2). |
| Oct. 13. | Germans execute the English nurse, Edith Cavell, for aiding Belgians to escape from Belgium. |
| Oct. 14. | Bulgaria declares war on Serbia. |
| Oct. 15—19. | Great Britain, France, Russia, and Italy declare war against Bulgaria. |
| Nov. 10—Apr. | Russian forces advance into Persia as a result of pro-German activities there. |
| Dec. 1. | British under General Townshend retreat from near Bagdad to Kut-el-Amara. |
| Dec. 3. | United States government demands recall of Captain Boy-Ed and Captain von Papen, attaches of the German embassy. |
| Dec. 6. | Germans capture Ipek, in Montenegro. |
| Dec. 15. | Sir Douglas Haig succeeds Sir John French in command of the British army in France. |
| Dec. 19. | British forces withdraw from parts of Gallipoli peninsula. |
| June 7. | British blow up Messines Ridge, south of Ypres, and capture 7500 German prisoners. |
| June 10. | Italian offensive in Trentino. |
| June 12. | King Constantine of Greece forced to abdicate. |
| June 17. | Portuguese troops on west front. |
| June 26. | First American troops reach France. |
| June 29. | Greece enters war against Germany and her allies. Allenby takes command in Palestine. |
| July 1. | Russian army led in person by Kerensky, the minister of war, begins an offensive in Galicia, ending in disastrous retreat (July 19-Aug. 3). |
| July 20. | Kerensky succeeds Prince Lvoff as premier of Russia. |
| July 31-Nov. 6. | Battle of Flanders (Passchendaele Ridge); British successes. |
| Aug. 15. | Peace proposals of Pope Benedict published (dated Aug. 1). United States replies Aug. 27; Germany and Austria, Sept. 21. |
| Aug. 15. | Canadians capture Hill 70, dominating Lens. |
| Aug. 19-24. | New Italian drive on the Isonzo front. |
| Aug. 20-24. | French attacks at Verdun recapture high ground lost in 1916. |
| Sept. 4. | Riga captured by Germans. |
| Sept. 8. | Luxburg dispatches ("Spurlos versenkt") published by United States. |
| Sept. 15. | Russia proclaimed a republic. |
| Oct. 17. | Russians defeated in a naval engagement in the Gulf of Riga. |
| Oct. 26. | Brazil declares war on Germany. |
| Oct. 24-Dec. | Great German-Austrian invasion of Italy. |
| Oct. 27. | Fall of Cividale; |
| Oct. 28. | fall of Gorizia; |
| Oct. 29. | fall of Udine; |
| Oct. 31. | Italians reach the Tagliamento in the retreat; |
| Nov. 4. | British troops reach Italy; |
| Nov. 9. | Italian line withdrawn to the Piave and there established. |
| Nov 2. | Germans retreat from the Chemin des Dames, in France. |
| Nov 3. | First class of Americans with German soldiers. |
| Nov 4. | British troops reach Italy. |
| Nov 7. | Overthrow of Kerensky and provisional government of Russia by the Bolsheviki. |
| Nov 9. | Italians on the Piave. |
| Nov 9. | British capture Gaza. |
| Nov 9. | Versailles Supreme War Council established. |
| Nov. 13. | Clemenceau succeeds Rihot as French premier. |
| Nov. 20-Dec. 13. | Battle of Cambrai. |
| Nov.29. | First plenary session of the Interallied Conference in Paris. Sixteen nations represented. Colonel P. NI. House, chairman of American delegation. |
| Dec. 3. | Conquest of German East Africa completed. |
| Dec. 6. | United States destroyer Jacob Jones sunk by submarine, with loss of over 60 American men. |
| Dec. 6. | Rumania agrees to armistice with Germany. |
| Dec. 7. | United States declares war on Austria-Hungary. |
| Dec. 9. | Jerusalem captured by British. |
| Dec. 22. | Peace negotiations opened at Brest-Litovsk between Bolshevik government and Central Powers. |
| Dec. 28. | President Wilson takes over the control of railroads. |
| Jan. 8. | President Wilson sets forth peace program of the United States. |
| Jan. 18. | Russian Constituent Assembly meets in Petrograd. |
| Jan. 19. | The Bolsheviki dissolve the Russian Assembly. |
| Jan. 28. | Revolution begins in Finland; fighting between "White Guards" and "Red Guards." |
| Jan. 28-29. | Big German air raid on London. |
| Jan. 30. | German air raid on Paris. |
| Feb. 1. | Germany and Austria-Hungary recognize the Ukrainian Republic. |
| Feb. 3. | American troops officially announced to be on the Lorraine front near Toul. |
| Feb. 5. | British transport Tuscan in with 2179 American troops on board torpedoed and sunk; 211 American soldiers lost. |
| Feb. 9. | Ukrainia makes peace with Germany. |
| Feb. 10. | The Bolsheviki order demobilization of the Russian army. Formal announcement that Russia was no longer a participant in the war. |
| Feb. 14. | Bolo Pasha condemned for treason against France; executed Apr. 16. |
| Feb. 17. | Cossack General Kaledines commits suicide. Collapse of Cossack revolt against the Bolsheviki. |
| Feb. 18-Mar. 3. | Russo-German armistice declared at an end by Germany; war resumed. Germans occupy Dvinsk,Minsk, and other cities. |
| Feb. 21. | German troops land in Finland. |
| Feb. 21. | British cilia ure Jericho. |
| Feb. 23. | Turkish troops drive back the Russians in the northeast (Trebizond taken Feb. 26, Erzermn Mar. 14). |
| Mar. 2. | German and Ukrainian troops defeat the Bolsheviki near Kief in Ukrainian. |
| Mar. 3. | Bolsheviki sign peace treaty with Germany at Brest-Litovsk. Ratified by Soviet Congress at Moscow, Mar. 15.
|
| Mar. 7. | Finland and Germany sign a treaty of peace. |
| Mar. 10. | Announcement that American troops are occupying trenches at four different points on French soil. |
| Mar. 11. | Great Gerrnan air raid on Paris, by more than fifty planes. |
| Mar. 13. | German troops occupy Odessa on Black Sea. |
| Mar. 21–Apr. 1. | First German drive of the year, on 50-mile front, extending to Montdidier. |
| Apr. 5. | British and Japanese armies landed at Vladivostok. |
| Apr.9–18. | Second German drive, on a 30-mile front between Ypres and Arras. |
| Apr. 14. | Foch commander in chief. |
| May 6. | Rumania signs peace treaty with the Central Powers. |
| May 7. | Nicaragua declares war on Germany and her allies. |
| May 9-10. | British naval force attempts to block Ostend harbor. |
| May 14. | Caucasus proclaims itself an independent state; but the Turks overrun the southern part, and take Baku Sept. 19. |
| May 24. | Costa Rica declares war on the Central Powers. |
| May 25–June. | German submarines appear off American coast and sink 19 coast-wise vessels, including Porto Rican liner Carolina, with loss of 16 lives. |
| May 27–June 1. | Third German drive, capturing the Chemin des Dames and reaching the Marne River east of Chilteau-Thierry. American marines and French in Chilteau-Thierry sector. |
| May 28. | American forces near Montdidier capture village of Cantigny and hold it against numerous counter-attacks. |
| May 31. | United States transport President Lincoln, sunk by U-boat while on her way to the United States ; 23 lives lost. |
| June 9–16. | Fourth German drive, on 20-mile front east of Montdidier, makes only small gains. |
| June 10. | Italian naval forces sink one Austrian dreadnought and damage another in the Adriatic. |
| June 11. | American marines take 8011 prisoners in Bellew Wood. |
| June 14. | Turkish troops occupy Tabriz, Persia. |
| June 15. | Official announcement that there are 800,000 American troops in France. |
| June 15-July 6. | Austrian offensive against Italy fails with heavy losses. |
| June 21. | Official statement that American forces hold 39 miles of French front in six sectors. |
| July 10. | Italians and French take Herat in Albania. |
| July 13. | Czecho-Slovak troops occupy Irkutsk in Siberia. |
| July 15-18. | Anglo-American forces occupy strategic positions on the Murman Coast in northwestern Russia. |
| July 15-18. | Fifth German drive extends three miles south of the Marne, but east of Rheims makes no gain. |
| July 16. | Ex-Tsar Nicholas executed by Bolshevik. |
| July 18-Aug. 4. | Second battle of the Marne, beginning with Foch's counter, offensive between Soissons and Château-Thierry. French and Americans drive the Germans back from the Marne nearly to the Aisne. |
| July 27. | American troops arrive on the Italian front. |
| July 31. | President Wilson takes over telegraph and telephone systems. |
| Aug. 2. | Allies occupy Archangel in northern Russia. |
| Aug. 8-Sept. | Allies attack successfully near Montdidier, and continue the drive until the Germans are back at the Hindenburg Line giving up practically all the ground they had gained this year. |
| Aug. 15. | American troops land in eastern Siberia. |
| Sept. 3. | The United States recognizes the Czecho-Slovak government. |
| Sept. 12-13. | Americans take the St. Mihiel salient near Metz. |
| Sept.15. | Allied army under General D'Esperey begins campaign against Bulgarians. |
| Sept. 16. | President Wilson receives an Austrian proposal for a peace conference, and refuses it. |
| Sept. 22. | Great victory of British and Arabs over Turks in Palestine. |
| Sept. 26. | Americans begin a drive in the Meuse valley. |
| Sept. 30. | Bulgaria withdraws from the war. |
| Oct. 1. | St. Quentin (on the Hindenburg Line) taken by the French. |
| Oct 1. | Damascus captured by the British. |
| Oct 3. | King Ferdinand of Bulgaria abdicates. |
| Oct 3. | Lens taken by the British. |
| Oct 4. | Germany asks President Wilson for an armistice and peace negotiations; other notes Oct. 12, 20, etc. similar notes from Austria-Hungary Oct. 7, and from Turkey Oct. 12. Wilson replies Oct. 8, 14, 18, 23. |
| Oct 7. | Beirut taken by a French fleet. |
| Oct 8. | Cambrai taken by the British. |
| Oct 13. | Laon taken by the French. |
| Oct 17 | Ostend taken by the Belgians. |
| Oct 17 | Lille taken by the British. |
| Oct. 24-Nov. 4. | Allied forces (chiefly Italians) under General Diaz win a great victory on the Italian front. |
| Oct. 26. | Aleppo taken by the British. |
| Oct. 31. | Turkey surrenders. |
| Nov. 1. | Serbian troops enter Belgrade after regaining nearly all of Serbia. |
| Nov. 3. | Trieste and Trent occupied by Italian forces. |
| Nov. 4. | Surrender of Austria-Hungary. |
| Nov. 5. | President Wilson notifies Germany that General Foch has been authorized by the United States and the Allies to communicate the terms of an armistice. |
| Nov. 6. | Mutiny of German sailors at Kiel; followed by mutinies, revolts, and revolutions at other German cities. |
| Nov. 7. | Americans take Sedan. |
| Nov. 9. | British take Maubeuge. |
| Nov. 9. | Abdication of the German emperor William II and the crown prince; they flee to Holland Nov. 10. |
| Nov. 11. | Armistice signed. |