The great siege of Gibraltar 1779-1783 was the British army's longest ever siege. It's an action that had passed me by, until I picked up a copy of James Faulkner's book, 'Fire Over the Rock'.
Britain had captured Gibraltar in 1704, during the War of the Austrian Succession and Spain understandably wanted it back. A Britain distracted by the American War of Independence was an opportunity not to be missed and a Spanish and French army started a formal siege. A frontal assault on Gibraltar from the Spanish mainland is a very difficult undertaking. Forts and siege lines were constructed, but no assault was tried during the whole four year siege.
Starving the garrison, led by the resourceful General Sir George Elliot, depended on the Spanish Navy. However, the currents in the channel around Gibraltar meant that enterprising blockade runners managed to avoid them throughout the siege. These supplemented three major relief convoys that fought their way in. The British and Hanoverian garrison of some 6,000 men held out against over 30,000 besiegers.
Interestingly, many in the British military establishment didn't regard Gibraltar as an important asset.They would have preferred to hold onto Minorca. In an age of smoothbore cannon, it was easy enough to get into the Med avoiding interference from the Rock. In the end, it was public opinion that made it difficult for the King and his advisors to negotiate a way out.
Sieges are rarely as interesting a story as battles, but Faulkner does a good job with this epic.