Akkadian is the oldest Semitic language, and one of the earliest and longest attested languages (ca. 2500 to 500BC). Its richly documented history contains a large corpus of letters written in a spontaneous and colloquial style, which are as close to the spoken language as can be expected from any written genre. Using this unique historical corpus, Guy Deutscher examines the development of complements and other subordinate structures in Akkadian over a period of two millennia. The book addresses various theoretical issues relating to sentential complementation, and attempts to resolve these by maintaining a strict division between a functional and a structural perspective. The diachronic changes in Akkadian are examined from these two different perspectives. The structural history follows the development of new structures: it describes how finite complements first emerged from adverbial clauses, only during the historical period. It also traces the slow grammaticalization of a quotative construction, over a period of two millennia. The functional history charts the changes in the roles of existing structures over time. It shows how, during the history of the language, finite subordination became more widespread, whereas other structures (e.g. infinite complementation and parataxis) receded. Finally, the developments in Akkadian are examined from a comparative perspective, and are shown to have parallels in many other languages. It is suggested that some of the historical changes in Akkadian may be seen as 'adaptive', and related to the development of more complex patterns of communication in a more complex society.