This thesis is a theoretical study which attempts to apply and integrate the field of complex systems to archaeology. In the first part of the thesis I will investigate the long run patterns of evolution of human societies at the macro scale through the frame of complex adaptive systems, which will uncover insights into the punctuated patterns of the development of human societies to (on average) greater levels of complexity and scale. From there I will construct a hypothetical model to explain the dynamics of this process, which is the feedback mechanism between two mutually reinforcing forces, innovation and re-organisational demands. In the second part analysis will move to the micro scale to attempt to explain urbanisation as an emergent phenomenon contingent on the processes of economic growth and development, which are the facilitators of increasing scale and complexity in human societies. As a case study, I will explore the emergence of the first urban centres in central Europe in the southeast Alpine region during the Early Iron Age, which helps demonstrate the way in which the theory is put into practice. The thesis ultimately aims to develop the value of complexity theory to the archaeologist interested in modelling human societies in the past.