You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Dissolution_of_the_Soviet_Union

Context:
This liberalization, however, fostered nationalist movements and ethnic disputes within the Soviet Union. It also led indirectly to the revolutions of 1989, in which Soviet-imposed communist regimes of the Warsaw Pact were peacefully toppled (Romania excepted), which in turn increased pressure on Gorbachev to introduce greater democracy and autonomy for the Soviet Union's constituent republics. Under Gorbachev's leadership, the Communist Party of the Soviet Union in 1989 introduced limited competitive elections to a new central legislature, the Congress of People's Deputies (although the ban on other political parties was not lifted until 1990).

Question:
What party did Gorbachev belong to?

Communist Party