The first time a Barbary macaque makes eye contact with you on the Rock of Gibraltar, you understand something immediately. This animal is not afraid of you. It is not even particularly interested in you. It is assessing whether you have food, whether your bag is open, and whether you are the kind of person who will panic when a monkey the size of a medium dog climbs onto your shoulder. There are around 230 Barbary macaques living wild on the Rock. They are divided into several social groups, each with its own territory, its own hierarchy, and its own attitude towards the thousands of tourists who walk through their home every day. Some groups are relaxed and approachable. Others are territorial and sharp. All of them are smarter than you expect. They are the only wild monkey population in mainland Europe. They have lived on the Rock for centuries, possibly millennia. A legend says that as long as the macaques remain in Gibraltar, the territory will stay British. Winston Churchill believed it. The British military maintained the colony as a matter of policy. And the monkeys, oblivious to geopolitics, kept doing what monkeys do: eating, grooming, fighting, breeding, and stealing things from tourists. Nobody knows for certain how the Barbary macaques arrived on the Rock of Gibraltar. There are three main theories, and all of them have problems. The first theory is that they were brought from North Africa by the Moors during their 700 year occupation of the Iberian Peninsula. Tariq ibn Ziyad crossed the strait in 711 AD, and the macaques may have come as pets, food, or simply stowaways. This is the most popular explanation, but there is no historical record of the Moors bringing monkeys to Gibraltar specifically. The second theory is that the British military imported them. After capturing Gibraltar in 1704, the British garrison may have brought macaques from Morocco as mascots or curiosities. Military records from the 18th century mention the apes, but none record their arrival. The third theory is the most interesting. Barbary macaques once ranged across southern Europe. Fossil evidence shows they lived in Spain, France, Italy, and as far north as Germany and Britain during warmer periods. The Gibraltar population may be a natural remnant, the last survivors of a European population that was wiped out everywhere else by climate change and habitat loss. If true, the macaques did not arrive in Gibraltar. They were always here. Genetic analysis has muddied the picture further. DNA studies show that the current population has been reinforced from Morocco multiple times, most recently during the 20th century. The macaques on the Rock today are descendants of both ancient European stock and more recent North African imports. The most famous chapter in the macaques' history involves Winston Churchill and a wartime emergency. By the early 1940s, the macaque population on the Rock had dropped to just seven individuals. Disease, inbreeding, and wartime disruption had nearly wiped them out. In a territory that was being fortified as one of the most important naval bases in the Mediterranean, the decline of the monkey population was noticed at the highest levels. Churchill, who was aware of the legend linking the macaques to British sovereignty, issued a direct order. The population was to be maintained. Reinforcements were to be brought from Morocco. The Army was given responsibility for the colony's welfare. Macaques were duly imported from the forests of the Middle Atlas in Morocco. The population recovered. The British stayed. And the legend, which might have been forgotten as a quaint superstition, was elevated into something closer to official policy. To this day, the Gibraltar Regiment (formerly the Royal Gibraltar Regiment) maintains a historical connection to the macaques. The colony is now managed by the Gibraltar Veterinary Clinic, which monitors health, manages population size through contraception programmes, and tracks every individual by name. The macaques live in groups of 10 to 50 individuals, each led by an alpha male and structured by a strict social hierarchy. The groups occupy different parts of the Upper Rock: some near the cable car top station, some around the Apes Den on Queens Road, some along the Mediterranean Steps, and some in the wilder southern sections of the nature reserve. A typical day starts at dawn. The group moves from its sleeping site to forage. Barbary macaques are omnivorous: they eat leaves, roots, seeds, insects, bark, and flowers. In Gibraltar, the natural diet is supplemented by the Gibraltar Ornithological and Natural History Society, which provides feed to ensure nutritional balance, and by whatever the monkeys can liberate from tourists. Grooming is the social glue. Macaques spend hours picking through each other's fur, removing parasites and reinforcing social bonds. Watching a grooming session on the Rock is oddly calming. Two adults will sit on a wall with the entire M