1872 In September, Austrian Emperor Franz Joseph I of Austria, Prime Minister Count Andracigula, Russian Emperor Alexander II and Prime Minister A.M. Gorchakov visited Berlin and met with German Emperor William I and Prime Minister Bismarck. The three prime ministers finally agreed to maintain the status quo in Europe; Work together to resolve disputes in southeast Europe. 1On May 6th, 873, German emperors William I, Bismarck and H.K.B von Mao Qi visited St. Petersburg, and Germany and Russia signed a military agreement. Agreement: When one contracting party is attacked by any European country, the other party will send 200,000 troops to help. On June 6th of the same year, Russian Emperor Alexander II and Gorchakov visited Vienna, and the emperors of Russia and Austria signed the Chin-Brown Agreement, which stipulated that in case of aggression by a third country endangering European peace, the two countries should immediately discuss the same course of action. In the same year, 10 year122 October, the German emperor also joined this agreement, which was valid until 1875, and was called the first san huang Union in history.

After the Berlin Conference, German-Russian relations deteriorated. Bismarck made himself attacked on both sides in order to prevent Russia and France from uniting; Russia also wants to unite Germany to compete with Britain in the Near East and the two straits, so Bismarck signed a three-country agreement with the Russian and Austrian ambassadors in Berlin on June 188 18. For a period of three years. 1884 updated, 1887 abolished. History is called san huang Second League. The agreement stipulates that when one of the contracting parties is at war with a fourth country, the other two countries should be neutral in good faith and try their best to localize the conflict; Any change to Turkey's European territory must be agreed by the three countries: the three countries recognize the principle of closing the Bosporus Strait and the Da Daniil Strait, and ensure that Turkey will not be used by any belligerent country for military activities. In addition, the three countries signed an additional agreement stipulating that Austria reserves the right to annex Bosnia and Herzegovina at any time; The three countries are not opposed to the merger of Bulgaria and East Rumilia. The agreement and agreement are confidential, and it was not disclosed until 1920. The 1887 agreement expired, but it was not renewed due to the intensified conflict between Russia and Austria in the Balkans. In the same year, Bismarck signed a reinsurance treaty with Russia, which lasted until 1890.