Your first chapter of your thesis or dissertation is meant to be an overview, for both your proposal of the first three chapters, and for your final defense of the entire document. This means that you will likely write this chapter three times. First, as you begin, in order to help you sort out the logic of the proposal without having to write about the literature or methodology with the depth required intheir corresponding chapters.
The Introductory Chapter is the Overview of Your PhD Dissertation Proposal:
If you go to the article on dissertation headings and subheadings, you will see that the introductory chapter is an overview of your research project. Some of the following headings are specific to education and will change slightly for other disciplines; nevertheless, all are germane to how to write a dissertation thesis. The purpose of this chapter is to set the stage of your study and it should include the following: