Edexcel IGCSE History: The Origins and Course of the First World War, 1905–18 (4HI1)

Historical Investigation A1, “The origins and course of the First World War, 1905–18”, is one of five investigation options in Section A of Pearson Edexcel International GCSE History (4HI1) Paper 2. It covers why rivalry between the great powers led to war in 1914, why the war on the Western Front became deadlocked, the war at sea and at Gallipoli, and why Germany was defeated in 1918. The exam question is source-based: you describe features, cross-reference two sources and evaluate a historian’s interpretation using the sources and your own knowledge.

Related: Revision notes | Practice questions | Paper 2 overview

Syllabus coverage

The 4HI1 specification (Issue 5, February 2026) sets five key topics for A1:

1. The alliance system and international rivalry, 1905–14 — the alliances and ententes, including the Triple Alliance and the formation of the Triple Entente; economic, imperial and military rivalry.
2. The growth of tension in Europe, 1905–14 — Balkan nationalism and Austro-Serbian rivalry, the Bosnian Crisis (1908–09) and the Balkan Wars (1912–13); Anglo-German rivalry, the naval race and the Moroccan Crises (1905–06 and 1911); Sarajevo and the outbreak of war.
3. The Schlieffen Plan and deadlock on the Western Front — the plan and its failure, trenches, new weapons, reasons for deadlock, the Somme and Passchendaele, and Haig’s responsibility.
4. The war at sea and Gallipoli — the German threat in the North Sea, raids, Heligoland Bight, Dogger Bank and Jutland; the U-boat threat, the Lusitania and anti-U-boat measures; the Gallipoli campaign, its evacuation and effects.
5. The defeat of Germany — US entry, the Ludendorff spring offensive (1918), the Allied advance (July–November 1918) and the reasons for German defeat.

How did the alliance system divide Europe?

By 1907 Europe was split into two armed camps. The Triple Alliance (1882) linked Germany, Austria-Hungary and Italy. France and Russia had allied in 1894; Britain settled colonial disputes with France in the Entente Cordiale (1904) and with Russia in 1907, forming the Triple Entente. The ententes were not binding military alliances, but they encouraged military planning together.

Rivalry had economic roots (Germany’s rapid industrial growth challenged Britain), imperial roots (Germany’s demand for a “place in the sun”) and military roots — conscript armies, war plans and an arms race. Each side’s defensive arrangements looked threatening to the other.

Why did tension grow between 1905 and 1914?

Anglo-German rivalry. Britain launched HMS Dreadnought in 1906, making older battleships obsolete and restarting the naval race on equal terms. Germany expanded its fleet under Admiral Tirpitz, and in 1909 the British public demanded more ships (“We want eight and we won’t wait”). Britain kept its lead, but the race poisoned relations.

The Moroccan Crises. In 1905 the Kaiser visited Tangier and declared support for Moroccan independence, testing the new Entente; at the Algeciras Conference (1906) Britain backed France and Germany was isolated. In 1911 Germany sent the gunboat Panther to Agadir; Britain again supported France, and Germany accepted part of the French Congo. Both crises strengthened the Entente rather than breaking it.

The Balkans. As the Ottoman Empire weakened, Balkan nationalism grew. In the Bosnian Crisis (1908–09) Austria-Hungary annexed Bosnia-Herzegovina, angering Serbia and Russia; Russia backed down when Germany supported Austria, but resolved not to be humiliated again. The Balkan Wars (1912–13) roughly doubled Serbia’s territory, making Austria-Hungary see Serbia as a serious threat.

Sarajevo and the July Crisis. On 28 June 1914 Archduke Franz Ferdinand was assassinated in Sarajevo by Gavrilo Princip, a Bosnian Serb linked to the Black Hand. Germany gave Austria-Hungary a “blank cheque” of support. Austria sent Serbia an ultimatum and declared war on 28 July. Russia mobilised; Germany declared war on Russia (1 August) and France (3 August) and invaded Belgium, and Britain, citing the 1839 Treaty of London guaranteeing Belgian neutrality, declared war on 4 August.

Why did the Western Front become deadlocked?

The Schlieffen Plan aimed to defeat France in about six weeks by sweeping through Belgium, before turning on Russia. It failed because Belgian resistance and the British Expeditionary Force (at Mons) slowed the advance, Russia mobilised faster than expected, Moltke weakened the right wing, and the French and British halted the Germans at the Marne (September 1914). Both sides then dug in, and by the end of 1914 trenches ran from the Channel to Switzerland.

Deadlock followed because defence was stronger than attack: machine guns, barbed wire and artillery made frontal assault deadly, while railways let defenders bring up reserves faster than attackers could advance. New weapons — poison gas (first used on a large scale at Ypres in 1915), tanks (first used on the Somme in 1916) and aircraft for reconnaissance — did not break the stalemate quickly. Life in the trenches meant mud, rats, lice, trench foot and constant shellfire.

The Somme (July–November 1916) was launched partly to relieve the French at Verdun; the British suffered about 57,000 casualties on the first day alone. Passchendaele (Third Ypres, July–November 1917) became notorious for mud. Haig has been criticised as a “butcher” who repeated costly attacks, and defended as a commander who wore down the German army and learned new tactics that won in 1918.

What happened at sea and at Gallipoli?

The German High Seas Fleet threatened Britain in the North Sea. German cruisers raided Scarborough, Hartlepool and Whitby (December 1914). Britain won at Heligoland Bight (1914) and Dogger Bank (1915). At Jutland (May–June 1916), the only major fleet battle, Britain lost more ships and men, but the German fleet returned to port and rarely ventured out again — so Britain kept control of the sea and its blockade of Germany.

U-boats were Germany’s main naval weapon. The sinking of the Lusitania (May 1915), with over 1,100 deaths including 128 Americans, damaged Germany’s relations with the USA. Unrestricted submarine warfare from February 1917 brought Britain close to starvation until convoys, depth charges, mines and Q-ships reduced losses.

Gallipoli was Churchill’s plan to knock the Ottoman Empire out of the war and open a supply route to Russia. A naval attack on the Dardanelles failed (March 1915); landings by British, French and ANZAC troops in April 1915 were pinned down on the beaches. The evacuation (December 1915–January 1916) was the most successful part of the campaign. Effects: heavy casualties, Churchill’s resignation from the Admiralty, and a strong sense of national identity in Australia and New Zealand.

Why was Germany defeated in 1918?

The USA entered the war in April 1917 because of unrestricted submarine warfare and the Zimmermann Telegram. With Russia out of the war, Germany launched the Ludendorff spring offensive (March 1918), using stormtroopers and surprise bombardments. It gained ground but exhausted Germany’s best troops and left long, exposed lines. From July 1918 the Allies counter-attacked; at Amiens (8 August) tanks, aircraft and artillery combined effectively, and the Hindenburg Line was broken in September. Reasons for defeat: the blockade and hunger at home, American troops and resources, improved Allied tactics, the failure of the spring offensive, the collapse of Germany’s allies and revolution at home. The armistice was signed on 11 November 1918.

Frequently asked questions

How is this option examined? Through sources and an interpretation; you need enough context to judge what unseen sources say and leave out.

Was the alliance system the main cause of the war? Weigh it against the naval race, the Balkan crises, imperial rivalry and the decisions of July 1914.

Was Haig a “butcher”? A classic interpretation question: use evidence on both sides.

Official syllabus

Pearson Edexcel International GCSE History (4HI1) specification, Issue 5, February 2026, Paper 2, Historical Investigation A1 — qualifications.pearson.com.