Systems-of-Systems (SoS) have become increasingly complex and are frequently used in highly distributed, dynamic, and open environments. SoS have emerged as a new class of evolving software systems, where constituent systems (themselves systems in their own right) work cooperatively in order to fulfill specific missions. SoS are characterized by managerial independence, geographic distribution, evolutionary development, and creation of emergent behavior. These characteristics have therefore raised substantial challenges to software engineering researchers and practitioners. SoS is becoming a hotspot, from both the research and the industrial viewpoints, in particular, related to crucial classes of applications such as safety-critical or mission-critical SoS. Furthermore, SoS are increasingly involved in applications that address societal needs such as environmental monitoring, distributed energy grids management, emergency coordination and crisis management, global traffic control, and smart cities. In this context, the research topic of software architecture for SoS needs to receive more attention and research efforts, considering that software architecture is also the fundamental element to adequately design, implement, operate, and even evolve such dynamic, complex SoS. However, there is a lack of forums that discuss SoS from the Software Engineering perspective, including Software Architecture. Indeed, this workshop series is the first that addresses specifically this new perspective. The main goal of SESoS is to provide a forum for software architecture researchers and practitioners to exchange ideas and experiences, analyze research and development issues, discuss promising solutions, and propose inspiring visions for the future. This workshop will be held in conjunction with the ECSA 2014, in Vienna, Austria.