This paper discusses the reach of ecclesiastical power in Hobbes' Leviathan, examining how the State acquires some of the roles traditionally played by the Church. I will first contextualize historically the ecclesiological debates on which Leviathan draws. Then, I will examine the essential role Hobbes assigns to the king in the governance of the church. Although Hobbes' political theology is often deemed atheist, in Leviathan the king becomes the institutional head of the Church. Moreover, he should establish a minimal Christian (...) creed to be shared by his subjects, in order to preserve religious peace among the different churches of his kingdom. (shrink)