The German Empire during World War I was led by Wilhelm II who, as emperor of Germany, was the head of state. The chief of government was the chancellor, Theobald von Bethmann-Hollweg and, in the war's waning days, Georg von Hertlin. The chief of the German Army's general staff for most of the war was Field Marshal Paul von Hindenburg.
However, it should be noted that Germany at this time was a confederation of semi-autonomous kingdoms, city-states, and principalities, each with their own political leadership. Wilhelm II, for instance, was both German Emperor and King of Prussia. One of the most powerful constituent states of the empire, after Prussia, was Bavaria. Its king, Ludwig II, fruitlessly attempted at one point to negotiate a separate peace with the Entente powers.
A number of political parties were represented in parliament, including: the Conservative Party, the Social-Democratic Party, the Centre Party, and the National Liberal Party.
The leadership of Germany during WWI included Kaiser Wilhelm II and the German Chancellor, Theobald von Bethmann-Hollweg. Wilhelm became Kaiser in 1888 upon the death of Frederick III. In 1909 he appointed Bethmann-Hollweg Chancellor. Bethmann-Hollweg was a supporter of Wilhelm II, and was the real ruler as Wilhelm II’s behavior became erratic. As WWI began, Bethmann-Hollweg’s power and influence began to wane and the power of the German military grew. In July of 1917 Bethmann-Hollweg was force to resign and Germany became in reality a military dictatorship under the control of General Paul von Hindenburg and Colonel Erich Ludendorff.