In this book DH Green uses the changes in and development of Germanic languages to provide evidence of Germanic cultural and societal changes, and to discuss how interactions between different cultures impacted these changes, during the late Roman and Early Medieval periods.
The book is divided into three main sections. In the first Green tracks the evolution of Germanic culture and uses language evidence to show how culture changed over time. In the second section Green, largely through the use of loanwords, shows how different population groups such as Goths, Alamanni, Romans, etc., impacted Germanic culture. In the third section he follows the Christianization of Germanics and shows how this occurred, both in terms of geographical spread as well as the methods used in conversion.
I think there are two ways to read this book. One is as a linguist or philologist, examining how Germanic languages evolved through cultural changes. The other way is as a work where cultural or societal changes are traced through the evolution of language, and as a study of what language can tell us about these changes. I used this second method myself - considering language as another piece of evidence to add to textual and archaeological evidence which I'm more familiar with.
I've read some reviews which state that knowledge of Germanic languages or Latin would be valuable before reading this book. As someone with almost no knowledge of Germanic and only a passing familiarity with Latin, I don't agree with this. While some knowledge might make it a bit easier to read, I don't believe it's required. I don't need to know whether Clovis was converted to Christianity in 496 or 507 to understand the implications of this for Merovingian Gaul. Similarly, I don't need to memorize "truhtin" or "kuning" to follow the discussion involving how the uses of these words indicate a movement from where the leader was a temporary head of a war-band to one where the leader was a hereditary king. Nor do I need to know the word "frauja" to follow its discussion and how it implied a depiction of God as pacifist in early attempts at conversion and to contrast it with later acceptance of God as a military figure helping lead Christians to success in war.
Rather than having some knowledge of the study of language, I'd recommend that you only read this if you're fairly familiar with the development of Germanic society from the 4th through the 7th centuries. This will allow you to take Green's linguistic evidence, which is considerable, and use it to enhance your knowledge. He does not provide any sort of narrative history and dives right into discussing specific concepts. If you're reading this as one of your first books on Late Antiquity or Germanic society, I think it would be very easy to become lost.
This was an interesting book. I was familiar with most of the Germanic cultural changes Green discusses, however the use of language provides an interesting perspective and the detailed way in which word usage is discussed helped provide some additional specifics into how culturasl change happened. As an example, the language Ulfila used in his early translation of the Bible into Gothic provides a very interesting window into how early Christianity stressed God as a peaceful deity and how important this was in the 4th century, while this point of emphasis was largely gone by the 6th when the concept of God bringing success in warfare was noted as a reason for Clovis and others to convert.
Not being a linguist, I'm unable to comment on the accuracy of Green's evidence and his use of it. However I will say that he provides very sound reasoning and he uses a great deal of detail to illustrate exactly what language changes revealed about changes in society. The arguments are detailed and must be followed with care. This is not a book I could just casually read (perhaps it would be for a philologist) and at times it became very dense. There are some specific aspects, such as feudalism and some migration patterns, where I question stated assumptions. In addition, the footnoting is sparser than I'm used to and many of Green's sources are quite old.
Nevertheless, it's worthwhile for the new perspective it provides, particularly when it comes to using language as evidence. I always knew language was used in this way, however this book gave me a much fuller understanding of how.