The post-war period in the history of Germany came to the end in 1949 with split of the country to the FRG and the GDR. The reasons of this split were caused not only by policy of the occupational authorities, but also lack of unity in those political structures which worked in West Germany and in the Soviet occupational zone (since 10/7/1949 - the GDR). The purpose of this article is the analysis of the specific historical conditions, which developed in West Germany in which there was a formation of two Christian parties: The Christian Social Union in Bavaria (CSU) and the Christian Democratic Union, which united in themselves Catholics and Protestants and concluded among themselves the fractional agreement existing until present. Sources of this subject are documentary materials on stories of CDU and CSU, Economic and Parliamentary councils, statistical data on elections to the Bundestag of Germany and stories of Christian democracy in Germany, researches of the German historians and political scientists and also Soviet and Russian experts. Memoirs of Konrad Adenauer and Franz Josef Strauss; biography of Helmut Kohl, Wolfgang Schaeuble, Teo Vaygel, Horst Zeekhofer, Angela Merkel were attracted with the author. Creation of CSU in Bavaria happened earlier than CDU (the first congress took place in 1950 in Goslar). Specifics of Bavaria, the Bavarian conservatism and patriotism caused the regional status of CSU. However, its creators wished bigger: representative offices of the party at the federal level. In it their ambitions coincided with plans of founders of CDU, first of all, of Adenauer who moved forward for the first roles in the course of institutionalization of West Germany. The agreement on joint activity between CSU and CDU was signed with the beginning of work of Economic council. Christian parties could block the aspiration of social democrats to enter planned economy in West Germany. Without having allies, SPD could not prevent transition to social market economy. After elections to the Bundestag of 1949, CDU and CSU formed uniform parliamentary fraction which remained ruling till 1969. The allied unity of CDU/CSU was exposed to crisis more than once. Especially sharp disagreements between parties were in the late seventies when the ambitious politician F.J. Strauss was the chairman of CSU. In recent years the Bavarian union sharply criticized the chancellor Angela Merkel for immigration policy which weakened support of parties from voters. Thereby the social and political situation in Germany forces CDU/CSU to look for new opportunities for preservation of the interparty union.
