The aim of this book is to explore the interdisciplinary relationships between archaeology and other branches of knowledge in Europe and elsewhere. Interdisciplinary cooperation has been essential in the development of archaeology as we know it today, although until now its role and influence have been largely ignored in the histories of the discipline. This book brings to light the processes that led to interdisciplinary relations in archaeology from the 19th to the 20th centuries, with scholarly contributions that offer a critical overview of this complex, dynamic and long-lasting transformative process. This is a pioneering project in the field of the history of archaeology, as it is the first to examine the inclusion into archaeological practice of various disciplines categorised under the umbrella of hard, natural and social sciences, as well as the humanities. This insertion led to ground-breaking interdisciplinary collaborations and, ultimately, to the birth of new branches within archaeology, including, for example, archaeozoology, archaeobotany, geoarchaeology and archaeometallurgy. The authors of this volume include internationally acknowledged scholars of the history of archaeology. Chapters cover a wide range of topics, looking at interdisciplinarity in archaeology at a general level by analysing its relationship with a number of other sciences in specific countries such as Portugal and Italy, to the incorporation of particular disciplines such as geology, palynology and zoology into archaeology using case studies. Several authors focus on the work of influential scholars as starting points for examining the intersection between antiquarianism, archaeology, the natural sciences and numismatics or between archaeology, art history, architecture and natural sciences. Other chapters theorise on the influence of epistemology and philosophy of science and even positivism on archaeological theory and practice. The influence of the army is also discussed in the development of underwater and aerial archaeology.