Peace with Honour is the name of the treaty between the Central Powers (Germany, Austria-Hungary, Ottoman Empire and Bulgaria) and the remaining free powers of the Entente (the British Empire and its Dominions, Portugal and Japan) which officially ended the Weltkrieg.
The Armistice Years
Although the Weltkrieg technically ended with the 1919 ceasefire, it continued in proxy conflicts like the Irish Civil War. By 1921, the stalemate had only worsened. In the Middle East the Ottoman Empire was in shambles are unready to attack the Arab revolters or cross the Suez Canal, where British forces were entrenched, and Germany was not in a position to attempt a naval invasion of the British Isles, let alone Portugal or Japan. The British had been unable to put down the Irish rebellion, and were in no shape to resume the war, her allies even less so. The war had strained the economy of every country involved, and proved the internal weaknesses of both Austria-Hungary and the Ottoman Empire. All of Germany's colonies save East Africa were occupied, but it had clearly won the war, even if a total victory was impossible. It was obvious to everybody that the time had come to negotiate.
In November of 1921, General Ludendorff presented to Lloyd-George the "Peace With Honour" agreement. Under its terms, Britain would acknowledge Germany's gains from the war, while Germany would respect the imperial possessions of the remaining Entente powers of Britain, Japan, and Portugal. The occupied German colonies were to be returned and the Ottoman Empire would gain control over Cyprus.
The treaty was formally signed on November 11th, 1921, declaring the end of the Weltkrieg after more than 7 years of a war that had changed the destiny of Europe forever.