Great Siege of Gibraltar prints by Lt George Frederick Koehler

This striking set of prints depicts the Great Siege of Gibraltar (June 1779 to February 1783), the longest siege ever defended by British Armed Forces.

Though often overlooked, the siege was part of the wider American War of Independence. Spanish and later French forces, supporting the American colonies, blockaded the British garrison by land and sea.

The sketches were drawn by Lieutenant George Frederick Koehler, who arrived in Gibraltar with one of the relief convoys in the spring of 1782. Artillery officers at the time were trained in drawing, due to the need to visualise enemy positions and terrain. Koehler was clearly a skilled artist, but this wasn’t his only talent. He is also remembered for inventing a gun carriage that allowed the axis of the gun to be depressed to an angle of seventy degrees. This design made full use of Gibraltar’s elevation, enabling defenders to fire from high ground. While the idea wasn’t entirely new, Koehler’s innovation—the sliding carriage—allowed the gun to recoil without lifting the entire structure into the air. The principle was later incorporated into more conventional artillery carriages.

Several of Koehler’s drawings depict the major assault on 13 September 1782, which involved an artillery bombardment from both land and sea. The attacking forces deployed specially adapted ‘battering ships’—floating artillery platforms designed to break British defences. At the time, five companies of the Royal Artillery were stationed on the Rock. Supported by trained infantrymen, they succeeded in destroying several battering ships; others were scuttled once it became clear the assault had failed.

The siege ended with the peace negotiations that concluded the American War of Independence.

Remarkably, the five artillery companies that served during the siege still exist today as 19, 5, 23, 22, and 21 Batteries of the Royal Artillery. Each proudly carries the honour title “Gibraltar 1779–83”.