Latin American liberation theology (Spanish: Teología de la liberación, Portuguese: Teologia da libertação) is a synthesis of Christian theology and Marxian socio-economic analyses, that emphasizes "social concern for the poor and political liberation for oppressed peoples". Beginning in the 1960s after the Second Vatican Council, liberation theology became the political praxis of Latin American theologians such as Gustavo Gutiérrez, Leonardo Boff, and Jesuits Juan Luis Segundo and Jon Sobrino, who popularized the phrase "preferential option for the poor". It arose principally as a moral reaction to the poverty and social injustice in the region, which Cepal, a leftist think tank, deemed the most unequal in the world.