Agentic AI systems, characterized by autonomous reasoning, decision-making, and coordinated multi-agent behavior, are rapidly transforming how software systems are designed, engineered, and governed. By combining generative AI, symbolic reasoning, reinforcement learning, and decentralized coordination, these systems introduce new architectural challenges related to autonomy, security, trust, sustainability, and sovereignty. Traditional software architecture approaches are often insufficient to address the emergent behavior, long-lived evolution, and governance requirements of agentic ecosystems. The International Workshop on Architecting Secure, Intelligent, and Sovereign Agentic Systems (ASISAS) provides a dedicated forum for researchers and practitioners to explore architectural principles, engineering methods, and governance strategies for next-generation agentic systems. The workshop positions software architecture as the unifying discipline to address security-by-design, runtime assurance, accountability, AI sovereignty, and sustainable lifecycle management of agentic systems. ASISAS welcomes research papers, experience reports, position papers, and visionary contributions addressing architectural design, security and trust mechanisms, and responsible agentic ecosystems.