For good reasons, a book of your own – now sometimes called a ‘monograph’, although this really only means a specialist work by a single author (and so technically could apply to a journal article) – is widely seen as the gold standard of historiography. Because history is an evidence-intensive subject, and also substantively extensive – that is, it aspires to both breadth and depth – there are many intellectual projects that can only be achieved at book length. This is why the professional qualification for academic historians – the Ph.D. – is achieved by writing a book-length dissertation, and it’s why hiring and promotion decisions are largely based on the publication of books.
Books are quite like Ph.D. dissertations – they tend to range from 80-120,000 words and often cover a similar stretch of ground. Why then don’t we just publish our Ph.D. dissertations (as is the case in some disciplines and in some countries)? There are a number of reasons for this. First, the tradition has been to consider the Ph.D. dissertation the first draft of a book. It gets examined and critiqued and the author can then go away and develop or transform it.
As we’ve said before, history is slow – the work matures over several iterations, with time to breathe and contemplate in between. It’s hard to teach someone how to write a book; it’s the kind of thing you learn by doing; and this takes time (so be sure to get friends, colleagues, mentors to read successive drafts of chapters, to help you make sure you’re on the right track). Second, the tendency in recent years has been to tightly control the time spent writing the Ph.D. and therefore to limit its scope. If it’s going to be published, it needs to regain the wider horizons that only extra time (and sometimes some extra words) can supply.
Many book versions of Ph.D.s involve extra chapters that take on entirely new extensions of the original conception, or more comparative or methodological reflections. Increasingly, postdoctoral fellowships are designed to give early-career researchers time to convert their dissertation into a book, rather than to launch a new project already. This may mean that there is a gap of 2-6 years (or more) between completion of the Ph.D. and publication of the monograph. It’s impossible to describe the ideal type book. Sometimes they range over centuries and continents. Sometimes they are tightly focused on a micro history, especially one which affords rich sources.
Some historical monographs are more like books in other disciplines – loosely-connected collections of case-studies, where the chapters read like stand-alone articles. Others are dominated by a cohesive thesis which plays itself out systematically through every page of the book. You’ll have your own tastes and ideas, probably honed further by writing the Ph.D.