This open access book is a groundbreaking exploration of systemic risk in modern financial systems. Through its theoretical and empirical investigations, it reveals the multidimensionality of systemic risk, the transmission channels of crises, and the interlinkages between physical, transition, and financial risks. It introduces cutting-edge methodologies, including prediction and optimization models based on complex networks, multilayer networks and eXplainable Artificial Intelligence (XAI) approaches, to forecast and measure systemic risk and financial crisis. It provides insight for academics, practitioners, policy and supervisory authorities, and bankers and financial market operators on understanding the links that determine the propagation of financial crises and the emergence of systemic risks. This book is essential for those wishing to better understand systemic risk and its implications.