In short
On January 10, 1920, the League of Nations held its first Assembly in Geneva, establishing the world's first permanent international organization designed to prevent war through collective diplomacy. Fifty-five nations sent delegates to adopt the League's constitution—a landmark attempt to replace great-power politics with rules-based cooperation after World War I left 20 million dead.
How it unfolded.
The five-minute version
What actually happened.
The League of Nations was established with three main constitutional organs: the Assembly; the council; the Permanent Secretariat. The two essential wings of the League were the Permanent Court of International Justice and the International Labour Organization.
As it was happening
13 voices, 9793 days.
One beat at a time. Click any dot on the timeline to jump, press play for autoplay, or use the arrow keys to step.
Treaty of Versailles signed
The peace treaty ending World War I included the Covenant of the League of Nations as its first 26 articles, committing signatories to the new organization.
Voices from this moment (1)
Treaty of Versailles signed
Jun 28
“The peace treaty ending World War I included the Covenant…”
As it was happening
13 voices, 9793 days.
Day 0 · June 28, 1919
Treaty of Versailles signed
The peace treaty ending World War I included the Covenant of the League of Nations as its first 26 articles, committing signatories to the new organization.
“The peace treaty ending World War I included the Covenant…”
- Treaty of Versailles signed, Jun 28
Day 196 · January 10, 1920
First Assembly convenes
The League of Nations Assembly meets for the first time in Geneva, with delegates from 55 nations adopting the League's constitutional structure and establishing three main organs: the Assembly, the Council, and the Permanent Secretariat.
“The League of Nations is constructed upon the foundation of…”
- The Economic Consequences of the Peace, published December 1919; reflections continuing into 1920, Jan 15
“The League of Nations Assembly meets for the first time in…”
- First Assembly convenes, Jan 10
Day 297 · April 20, 1920
Council holds first session
The League's executive Council, comprising permanent and non-permanent members, begins regular meetings to handle urgent matters between Assembly sessions.
“The League of Nations is the practical statesman's hope of…”
- Speech to the Assembly of the League of Nations, Geneva, Nov 15
“The League exists now.”
- The Times of London, Editorial, November 1920, Nov 16
“This assembly represents the birth of international law.”
- Opening sessions of the League Assembly, Geneva, November 1920, Nov 16
“The International Labour Organization gives teeth to social…”
- Address at the League Assembly, Geneva, November 1920, Nov 20
“The League's executive Council, comprising permanent and…”
- Council holds first session, Apr 20
Day 718 · June 15, 1921
Permanent Court of International Justice opens
The Court, one of the League's two essential wings, begins operations in The Hague to adjudicate disputes between member states.
“The Court, one of the League's two essential wings, begins…”
- Permanent Court of International Justice opens, Jun 15
Day 918 · January 1, 1922
International Labour Organization becomes League agency
The ILO, the League's second essential wing, officially becomes a specialized agency, pioneering labor rights and workplace standards across member nations.
“The ILO, the League's second essential wing, officially…”
- International Labour Organization becomes League agency, Jan 1
Day 5222 · October 14, 1933
Germany withdraws from League
Nazi Germany quits the League under Hitler, signaling the organization's inability to enforce compliance or prevent aggressive expansion.
“Nazi Germany quits the League under Hitler, signaling the…”
- Germany withdraws from League, Oct 14
Day 7370 · September 1, 1939
World War II begins
Germany invades Poland, exposing the League's fundamental weakness in maintaining collective security and preventing major-power aggression.
“Germany invades Poland, exposing the League's fundamental…”
- World War II begins, Sep 1
Day 9793 · April 20, 1946
League formally dissolves
The League of Nations officially ceases operations, with its assets and archives transferred to the newly formed United Nations.
“The League of Nations officially ceases operations, with…”
- League formally dissolves, Apr 20
The numbers.
3 numbers that anchor the scale.
By the numbers
The countable parts.
Number of founding nations
0
Member nations at League's peak
0
Years of operation before dissolution
0 (1920–1946)
Captured in time.
Captured before it changed
The web as it looked, the day it happened.
Wayback Machine snapshots of the pages people actually loaded that day. Click any card to open the archive at full size.
Sources & citations.
Sources
Where this came from.
Every claim on this page traces to a public, license-clean source. We don't asterisk well.
Wikipedia
1 source- 1.Assembly of the League of Nations
en.wikipedia.org