The problem is that I would like to use heading style 1 for the rest of the document. This can be seen in the contents page on the second screenshot as 'Introduction' is in line with the headings above it, but subheadings are indented.

If I used Roman numerals for heading one and changed all my current heading 1 headings to heading 2, they would appear indented on the contents page.

There must be a simple way of doing this, almost all books have a preface in which roman numerals are used for headings!

I read somewhere that I could use a style break and then have difference styles for before and after the introduction heading - but I dont know how to do this.