1914-1918-online: International Encyclopedia of the First World War
Freie Universität Berlin / Bayerische Staatsbibliothek
The single highest-authority free reference for this topic: open-access, peer-reviewed encyclopedia of the First World War from Freie Universität Berlin and the Bavarian State Library, with over 1,600 articles by more than 1,200 international scholars. Each entry carries a DOI and is citable. It answers almost any WWI sub-question (Eastern Front, colonial theatres, home fronts, war economies, memory) at scholarly depth with citations, replacing the need for a dozen thin encyclopedia or blog links.
More resources on World War I
The Great War
Week-by-week chronological retelling of 1914-1918 produced across four years with British Pathé archive footage, plus standalone episodes on the Eastern Front, Africa, the Ottoman theatre and the naval war. Its real value is coverage of theatres the standard narrative skips (East Africa, Caucasus, Isonzo, Mesopotamia) at a level a beginner can follow before opening Stevenson. Public history, not peer-reviewed scholarship.
Voices of the First World War (IWM Podcast)
Episodes assembled from the Imperial War Museums sound archive, using recorded interviews with soldiers, sailors, airmen, munitions workers, nurses and schoolchildren. Runs chronologically from the July crisis through the fronts, home front and armistice.
The Deluge: The Great War, America and the Remaking of the Global Order, 1916-1931
Argues the war made the United States the financial and political pivot of a new world order between 1916 and 1931, and traces how Britain, Germany, Japan, Russia and China each adjusted to that fact. Economic history run alongside diplomacy. Covers the 'global reach' half that Eurocentric survey books handle badly, and supplies the debt-and-finance mechanics that explain the 1920s. Genuinely advanced as it assumes the reader already knows the military narrative, which is why it sits above the survey and the peace-conference books rather than replacing them.
Paris 1919: Six Months That Changed the World
Account of the six months of the Paris Peace Conference: Wilson, Lloyd George and Clemenceau, the redrawing of borders across Europe and the Middle East, and the mandate system. Argues Versailles is routinely over-blamed for what followed in 1939.
The Sleepwalkers: How Europe Went to War in 1914
The best-argued modern treatment of the origins question and the book that reopened a debate settled since Fritz Fischer. Its rejection of the Fischer thesis remains actively contested. Reconstructs the July 1914 crisis chancellery by chancellery, giving unusual weight to Serbian and Balkan politics and arguing that responsibility for the war was shared rather than principally German.
Cataclysm: The First World War as Political Tragedy
Single-volume history that treats the war as a political problem rather than a purely military one: why states entered, why they kept fighting for four years, and why the fighting finally stopped. Covers every front and the war economies. It argues an explicit analytical thesis (the war as political tragedy) and grounds it in multi-archive research rather than narrative retelling.