Lighthouse keeper went slowly mad as he lived with corpse for four months

Robert Eggers' 2019 psychological horror The Lighthouse, featuring powerhouse performances from Willem Dafoe and Robert Pattinson, won acclaim - and even an Oscar nomination - for its striking black-and-white cinematography and surreal atmosphere.

The film narrates the tale of two nineteenth-century lighthouse keepers stranded at a remote New England outpost during a violent storm, with isolation, mistrust, and strange visions taking their toll.

While audiences and critics have debated the movie's symbolism and genre – part horror, part myth, part drama – what many viewers don't realise is that it was partly inspired by a real-life tragedy that took place more than 200 years ago on the far coast of Wales.

The true story, now known as the Smalls Lighthouse Tragedy, is one of the most harrowing episodes in British maritime history and led to a permanent change in lighthouse policy.

The Smalls Lighthouse stands on a rocky islet about 20 miles west of the St David's Peninsula in Pembrokeshire, exposed to the full force of the Irish Sea - designed and constructed in 1775, reports the Mirror.

Life at The Smalls was lonely and cramped. At the time, lighthouse crews were typically made up of just two men, who would spend long stretches in complete isolation.

Their only roles were to keep the lamp lit at night and maintaining the structure by day, no matter the weather.

In 1801, the lighthouse was manned by Thomas Howell and Thomas Griffith, two men who were reportedly known to quarrel. One day, Griffith fell seriously ill after what was described as a freak accident.

Howell tried to care for his colleague and set up a distress signal in the hope a passing vessel would relay their need for help. But this was an era without radio, and simple flag signalling was of little use for such a remote outpost.

Storms pounded the lighthouse for weeks, making it impossible for any ship to pass by. Griffith's condition worsened, and eventually, after a prolonged period of suffering, he died.

Faced with the sudden reality of being alone, Howell also confronted a chilling dilemma. Because the two men had not been on good terms, he feared if he disposed of the body at sea, any future inquiry would suspect him of murder.

His only option, he decided, was to keep the body until help arrived.

At first, Howell kept Griffith's body inside the living quarters, a hut barely five metres in diameter. But the stench of decomposition soon became unbearable.

A former cooper by trade, Howell dismantled part of the interior to build a makeshift coffin from timber boards. He placed Griffith inside, secured the lid, and hauled the coffin out to a shelf on the exterior of the lighthouse, tying it firmly in place.

The weather showed no signs of easing, and in the following weeks, the violent winds ripped the coffin apart, casting the planks into the sea and leaving the corpse tied to the railing, exposed to the harsh elements.

This is when the incident took on its most enduring – and gruesome – image. One of Griffith's arms had come loose, and whenever the wind caught it just right, it seemed to wave or beckon.

Howell could see it from inside the hut, a constant and eerie reminder of his dire situation.

As the days went by, several ships sailed within sight of the lighthouse, but the conditions were too treacherous to attempt a landing. Crews could see the light still burning at night – a testament to Howell's commitment to his duty – and during the day, they occasionally spotted a figure on the gallery.

From afar, they couldn't discern what had transpired, and with no apparent urgency in the signalling, they continued their journey.

It's thought Howell lived alongside his deceased colleague for approximately four months before a ship from Milford Haven was finally able to land on The Smalls.

When the rescuers arrived, they discovered Griffith's body still bound to the railings and Howell physically and mentally altered. Friends back on shore later claimed they didn't recognise him – his hair had prematurely turned grey, his face was gaunt, and he seemed shattered by the ordeal.

The Smalls Lighthouse Tragedy sent shockwaves through the maritime community, highlighting the perils of having only two keepers at such a remote station. As a result, the governing body changed its policy to mandate that all lighthouses be manned by at least three individuals at any given time.

This rule was upheld for nearly two centuries until the automation of British lighthouses in the late 20th century.

The tragic events of 1801 have inspired a plethora of works over the past two centuries. In 2011, the BBC aired The Lighthouse, a radio play penned by Alan Harris based on the tragedy.

In 2016, Welsh director Chris Crow unveiled a feature film bearing the same name, also loosely adapted from the events on The Smalls, before Robert Eggers' The Lighthouse brought the story to international audiences.