In preparation for the peace conference that was expected to follow World War I, in the spring of 1917 the British Foreign Office established a special section responsible for preparing background information for use by British delegates to the conference. The Congress of Berlin, 1878 is Number 154 in a series of more than 160 studies produced by the section, most of which were published after the conclusion of the 1919 Paris Peace Conference. The Congress of Berlin was convened by the major European powers to settle or at least manage without recourse to war what was known as “the Eastern Question,” or the problems arising from the gradual decline of the power of Ottoman Turkey in Europe and the rivalry among the other European powers for influence over the countries coming out from under the Ottoman yoke. The impetus to the congress lay with the Russo-Turkish War of 1877–78 and the resulting Treaty of San Stefano, which was regarded by the other European powers, Great Britain in particular, as so favorable to Russia that they demanded a revision. The participants in the Congress of Berlin were Austria, Britain, France, Germany, Italy, Russia, and Turkey. The decisions of the congress, embodied in the Treaty of Berlin of July 1878, included establishment of Bulgaria as an autonomous principality that was to remain nominally under Ottoman sovereignty; recognition of the independence of Montenegro and an increase in its territory; recognition of the independence of Serbia and Romania; and the transfer of certain territories in eastern Turkey to Russia. This study covers three main topics: the events immediately preceding the congress, the sessions of the congress, and the “precedents, encouragements, and warnings that it offers.” The study is by E.L. Woodward (1890−1971), fellow of All Souls’ College, Oxford, a prominent British historian perhaps best known for his multi-volume work, British Foreign Policy in the Second World War, published in the 1960s and 1970s.The Congress of Berlin, 1878 can be read in conjunction with History of the Eastern Question, Number 15 in this series, which includes the Treaty of Berlin as an appendix.