This chapter spans the history of European siege warfare across the long eighteenth century, from the age of Louis XIV to the Napoleonic Wars. It lays out the key thematic groundwork and siege case studies explored in later chapters. The first half outlines the nature of ‘the siege’ as the classic form of old-regime positional warfare – its operational forms, temporal and spatial dimensions, and rituals and customary laws of war – and charts the relative historic decline of breach assaults and siege related massacres of garrisons and civilians in the eighteenth century. The second half shifts to the Revolutionary-Napoleonic era. It identifies the continuing importance of siege operations beyond their earlier high point in European military affairs; the regional and chronological shifts in sieges across the Napoleonic Wars; the nature of British siege operations in Continental Europe and the colonial sphere (India and South America); and ends with an overview of British and French sieges in the Peninsular War – the epicentre of Napoleonic siege warfare and of the storming and sack of besieged towns.