Essentialists claim that we can distinguish between an object's essential and its accidental properties. Following important developments in modal logic during the 1960s and 70s, the orthodox view was that the essential properties of an object are its necessary properties. In his influential 1994 paper "Essence and Modality", Kit Fine argues that the orthodox view is wrong. His two main claims are that first, essentiality cannot be defined in terms of necessity and second, that necessity should instead be defined in terms of essentiality. In my dissertation, I aim to undermine both of his claims in order to defend a variation of the orthodox view. To do this, I first develop Fine's proposal for an essentialist definition of necessity into a more general essentialist theory of modality. I then raise a series of problems for the resulting theory. Finally, I introduce and defend a novel definition of essentiality in terms of metaphysical necessity and a notion of metaphysical dependence.