An outgrowth of a workshop held by the Community of European Solar Radio Astronomers (CESRA), this volume collects reviews on current research and perspectives on the variable solar corona: high-energy particles, large-scale disturbances such as mass ejections and waves, and radio diagnostics of the coronal plasma. Multiwavelength observations of the Sun with radio instruments and recent space missions are drawn on extensively, as well as input from neighbouring fields e.g. solar wind, Earth's bow shock. Recent developments are discussed alongside key developments in this rapidly evolving field.