New national identities

Poland reemerged as an independent country, after more than a century. As a "minor Entente nation" and the country with the largest casualties per head the Kingdom of Serbia and its dynasty became the backbone of the new multinational state, the Kingdom of Serbs, Croats and Slovenes (later renamed Yugoslavia). Czechoslovakia became a new nation. Russia became the Soviet Union and lost Finland, Estonia, Lithuania and Latvia, which became independent countries. The Ottoman Empire was soon replaced by Turkey and several other countries in the Middle East.

In the British Empire, the war unleashed new forms of nationalism. In Australia and New Zealand the Battle of Gallipoli became known as those nations' "Baptism of Fire". It was the first major war in which the newly established countries fought and it was one of the first times that Australian troops fought as Australians, not just subjects of the British Crown. Anzac Day, commemorating the Australian and New Zealand Army Corps, celebrates this defining moment.

After the Battle of Vimy Ridge, where the Canadian divisions fought together for the first time as a single corps, Canadians began to refer to theirs as a nation "forged from fire". Having succeeded on the same battleground where the "mother countries" had previously faltered, they were for the first time respected internationally for their own accomplishments. Canada entered the war as a Dominion of the British Empire and remained so afterwards, although she emerged with a greater measure of independence. While the other Dominions were represented by Britain, Canada was an independent negotiator and signatory of the Versailles Treaty.