The CSU, or Christlich-Soziale Union, is a conservative political party in Germany. It is active primarily in the state of Bavaria and is the sister party of the larger Christian Democratic Union (CDU), with which it forms a political alliance at the national level. The CSU is known for its strong emphasis on traditional values and its support for a socially conservative agenda. It has historically been a dominant force in Bavarian politics and currently holds the majority of seats in the state parliament.