HistoryData
Historical ConflictMarne basin

Second Battle of the Marne

The last major German offensive on the Western Front, its failure triggered the Allied advance that ended World War I 100 days later.

Duration & Scope

1918 ongoing

< 1 year

Key Facts

Dates
15–18 July 1918
Duration
4 days
Key weapon
Several hundred Renault FT tanks
Strategic consequence
Triggered Allied advance leading to armistice ~100 days later

Strategic Narrative Overview

The German assault began on 15 July 1918, crossing the Marne River on a broad front. However, French forces had anticipated the attack through intelligence and prepared elastic defenses. An Allied counterattack swiftly struck the German right flank, spearheaded by French infantry supported by several hundred Renault FT tanks. The combination overwhelmed German positions, inflicting severe casualties and halting the offensive within four days.

01 / The Origins

By mid-1918, Germany was under severe strain on the Western Front after years of attrition and the failure of earlier 1918 Spring Offensives to deliver a decisive breakthrough. German High Command launched a final offensive in the Marne region, hoping to split Allied lines, draw reserves away from Flanders, and force a negotiated peace before American troops could tip the balance decisively in the Allies' favour.

03 / The Outcome

The German failure at the Second Battle of the Marne proved irreversible. Unable to recover the initiative, German forces began a general retreat. The battle initiated the Hundred Days Offensive, a relentless Allied advance across the Western Front that progressively collapsed German resistance and culminated in the Armistice of 11 November 1918, ending the First World War.

Belligerents & Mobilization Analysis

Side A

1 belligerent

German Empire

Side B

2 belligerents

FranceAllied Powers
Outcome
Allied victory; German offensive repulsed with severe casualties, initiating the Hundred Days Offensive

Kinetic Engagement Axis

Major engagements timeline (1918–present)Timeline of major military engagements plotted chronologically.1918present1918Second Battle of…Side B

Scroll horizontally to view full axis. Events plotted relatively.

Side A victorySide B victoryInconclusiveDecisive / turning point

Location

Map of FranceMap of FranceFrance