As Europe progresses towards climate neutrality, the importance of energy storage in maintaining system stability and efficiency is underscored. Conventional storage systems often fall short in meeting the diverse demands of a system with high shares of renewable sources and decentralisation. Enter Hybrid Energy Storage Systems (HESS), which blend different technologies like batteries, supercapacitors, thermal storage, compressed air, hydrogen, and flywheels to offer a wide range of services from frequency regulation to seasonal energy shifting. HESS's operational flexibility enables it to cater to various applications, including industrial systems, grid services, remote environments, electromobility, and the built environment. Moreover, the industrial implications of HESS are significant, aligning with policies aiming to enhance clean technology capabilities and reduce external dependencies. Energy security and resilience benefits are notable, especially in light of the increasing renewables integration and the need for flexible storage solutions to manage grid volatility. Despite challenges such as standardisation, data limitations, and financial models, policy developments are emerging to pave the way for enhanced investment conditions in hybrid storage. Research projects like StoRIES are providing valuable resources like Technology Roadmaps and Strategic Research Agendas to guide stakeholders in implementing hybrid energy storage systems. By addressing technical challenges, integration strategies, and priority R&D areas, these initiatives aim to foster the widespread adoption of HESS across sectors, aiding Europe's transition towards a more sustainable energy landscape.