Formally incorporated into the domains of the Spanish crown in 1502, after centuries of occupation first by the Saracens and then by the Moors, the rocky peninsular of Gibraltar was fortified by the eminent siege engineer Daniel Speckle in the mid-sixteenth century and was thereafter considered impregnable by its new overlords. Despite this, after a determined siege lasting a mere three days, the fortress fell to allied English and Dutch forces in 1704 and has remained resolutely British until the present day.

Despite Spanish attempts to recover it by force in 1720 and again in 1727, it stayed in British hands remaining an affront to Spanish pride for the next fifty years. By 1779, with France and Spain now allied against an England preoccupied with her colonists' revolt in North America, a combined Franco-Spanish expedition commenced its operations against Gibraltar on 21st June that year and what became a truly epic siege continued until the Rock was finally relieved by the arrival of Admiral Lord Howe's fleet in mid-October 1782.

The need to repel these continual attempts to retake Gibraltar, coupled with the strategic importance of Britain holding the 'gateway to the Mediterranean', have occupied the Royal Navy through three centuries and this work by John Thomas Serres is a splendid example of how the Rock's vital importance became enshrined into England's national psyche.