On 1 June 1916, the country let out a collective sigh of relief.

‘I have arrived here,’ read Sir Ernest Shackleton’s cable from Port Stanley on the Falkland Islands. ‘The Endurance was crushed in the middle of the Weddell Sea.’

The astonishing news, which was published by the Manchester Evening News under the headline ‘Terrible Journey In Open Boat’, was the scoop of the year.

The reappearance of Shackleton, two years after he set off on his doomed voyage to one of the most inhospitable regions on earth, has become the stuff of legend – seen by many as one of the 20th century’s greatest triumphs of survival. One hundred years after his death in 1922, Shackleton’s achievements still embody the best of the ‘Heroic Age’ of Antarctic exploration, a period of unprecedented scientific and geographic exploration and stories of personal bravery that captured the public’s imagination in the early 20th century.

Shackleton’s first experience of the Antarctic came 15 years before his long-awaited cable from Port Stanley. In 1901, he secured a place on Robert Falcon Scott’s British National Antarctic Expedition, which aimed to ‘bring back a store of information which will largely increase our knowledge of what is present practically an unknown continent’. The RRS Discovery set sail on 31 July, with a supply of penguins to acclimatise the crew to an ‘Antarctic diet’. To Captain Scott’s surprise, the men were ‘by no means averse to it. Many pronounced it excellent.’ Shackleton proved himself a popular member of the team and was commended for his empathetic leadership style.

With the ship’s galley stocked full of fresh penguin, the Discovery arrived at the Antarctic coast on 8 January 1902. Alongside two other crew members, Captain Scott selected Shackleton for the march to the South Pole. The party set out on 2 November 1902, marching 40km a day through severe weather and punishing terrain. To compound their difficulties, all 22 dogs fell sick and perished, and the men suffered snow blindness, frostbite and scurvy. With food stocks in short supply, they pushed on, reaching as far south as 82° 17’ latitude – beating all previous records – but were ultimately beaten by the elements. Weakened by illness and hunger, they turned back. Shackleton was particularly affected; one of the diary entries on the return journey read, ‘Today he [Shackleton] is decidedly worse, very short winded and coughing constantly, with more serious symptoms that need not be detailed here…’

The men arrived back at the Discovery on 4 February 1903, and following a medical examination, Scott decided to send Shackleton home. Scott’s decision was not welcomed by Shackleton, who suspected Scott resented his popularity and natural flair for leadership. It marked the beginning of a private rivalry between the two men – in the words of Shackleton’s biographer Roland Huntford, his attitude to Scott turned to ‘smouldering scorn and dislike’, with the only remedy to his wounded pride being ‘a return to Antarctic and an attempt to outdo Scott.’

Once back on home ground, Shackleton was elected secretary of the Scottish Royal Geographical Society and married his wife, Emily, in 1904. Shackleton dabbled in both politics and business during his sojourn at home but made no secret of his real desire to return to the Antarctic at the head of his own expedition.

On 1 January 1908, Shackleton embarked on his second voyage to the Antarctic, aboard the ship Nimrod. By late October, Shackleton was ready to make his attempt on the South Pole. The team reached a new latitude of 88° 23’ south, only 112 miles from the Pole but, like the Discovery expedition, the attempt was fraught with challenges. One of the team was almost killed when a pony fell into a crevasse, taking with it a stock of rations. The loss of their supplies was a factor in Shackleton’s decision to abandon the attempt – it was now a race against starvation rather than a quest to secure a triumph – and the party existed on half rations for much of the return journey. Shackleton later revealed that the rations had depleted to only ‘two drops of cocoa and some salt and pepper’ and that if they had ‘gone on one day further to the South they would have been done’ (Luton Reporter, 10 February 1910). Despite this setback, Shackleton’s talent for keeping the crew’s spirits up by encouraging camaraderie and mutual respect marked him out as a natural leader and he acquired his famous nickname ‘the Boss’.

Shackleton returned to Britain to a hero’s welcome, and he was made Commander of the Royal Victorian Order and a knight, among other honours. He immediately embarked on an extensive lecture tour, thrilling audiences with his ‘story of real adventure’ – illustrating it via cinematographic films which the Croydon Chronicle described as ‘really remarkable…(which taking into consideration the difficulties under which they must have been taken, are little short of marvellous).’

Meanwhile, Shackleton’s old adversary Captain Scott was making another attempt on the South Pole, but it was Norwegian explorer Roald Amundsen who would become the first explorer to get there in 1911, pipping Scott to the post by a mere month. In a cruel twist of fate, Scott’s party succumbed to starvation and the elements on the return journey, and he died at the end of March 1912 – the first British man to reach the geographic South Pole.

Scott’s fate was unknown until February 1913, when Shackleton, along with the rest of the world, greeted the news with shock and disbelief. But Shackleton’s interest in the Antarctic was by no means diminished by Scott’s tragic end, and he began to plan his third and what would become his legendary expedition, on the ship Endurance.

The expedition departed in August 1914, just a few days after war was declared, and soon ran into trouble. Conditions in the Weddell Sea were almost impassable and by mid-January 1915, Endurance became trapped in an ice floe. Shackleton hoped that the warmer spring temperatures would free the vessel but when the temperature eventually rose, the ice splintered the ship’s hull. On 24 October water began pouring in and Shackleton gave the order to abandon ship, saying, ‘She’s going down!’ The crew transferred their provisions and equipment to the surrounding ice and spent the next six months camped on a floe, hoping it would drift towards a landing point. On 21 November, Shackleton and his men watched as Endurance finally slipped below the surface to a watery grave some 3000m below.

Over the coming months, in desperate and impossible conditions, Shackleton and his crew made several attempts to march across the ‘grinding, crunching, dissipating’ ice, which all failed. Undeterred and not yet ready to give up, Shackleton decided to trust in the drift of the ice but on 9 April 1916 the floe broke in two and the entire crew were forced into lifeboats. After a terrifying five-day voyage across the Weddell Sea, in which they faced blizzards and freezing wind, the men eventually landed on Elephant Island, a desolate mountain island covered in ice, 346 miles from where Endurance had sunk and 720 nautical miles from South Georgia.

The party had landed on solid ground, but they were hundreds of miles from any shipping routes, so the chance of rescue was unlikely. Shackleton and five other men bravely decided to risk an open boat journey on the lifeboat James Caird to South Georgia so they could raise the alarm. After 16 days sailing under the constant threat of 16m waves and hurricane force winds they finally sighted their destination. As the Dundee Courier later remarked – in the understatement of the year – the ‘long journey in a small boat’ had reached a successful conclusion.

The ordeal was far from over though. They had landed on the unoccupied side of the island, so to reach help they needed to cross the island. They only had 50 feet of rope, a carpenter’s adze, and boots with screws pushed into them for grip – and they were also exhausted. But with the knowledge that the fate of the 22 crew left behind rested on the success of the rescue party alone, they were able to muster the final dregs of their energy to march 32 miles in 36 hours over mountainous terrain with next to no equipment and hardly any food, reaching Stromness whaling station on 20 May.

With the help of the Chilean government and one of their navy tugs, the Yelcho, alongside British whaler Southern Sky, Shackleton returned to Elephant Island on 30 August 1916 – four and a half months after leaving it to get help. Remarkably, not one soul was lost – all 22 men had survived. Of those months the expedition’s photographer, Frank Hurley, shared his thoughts about Shackleton in 1917: ‘He attracted the entire party by his forceful character and inspired them with a confidence that not even the blizzard-swept pack ice or the weary months of waiting on Elephant Island could shake. It was to a large extent this confidence and implicit belief in their leader which enabled the party to work with unanimity and cohesion… Throughout the ordeal his cheerful manner in the face of apparent insurmountable obstacles induced the admiration and enthusiasm of all.’ (Carlow Sentinel, July 1917)

Shackleton’s heroic exploits and the publication of his account South, in December 1919, prompted another successful lecture tour. Then in 1921, he set out to circumnavigate the Antarctic on the Quest, despite concerns that his health wasn’t strong enough to endure another mission.

It was to be his final journey. Shackleton fell ill before the expedition had reached South Georgia but refused a medical examination or a return to England. Shackleton commented somewhat reflectively in his diary on 2 January 1922, ‘Ah me: the years that have gone since in the pride of young manhood I first went forth to the fight. I grow old and tired but must always lead on.’ Lead on he did, and the expedition continued, reaching South Georgia on 4 January 1922.

In the early hours of 5 January, Shackleton summoned physician Alexander Macklin to his cabin, complaining of discomfort. Macklin suggested Shackleton should take things easier in future, to which Shackleton famously replied, ‘You are always wanting me to give up things – what is it I ought to give up now?’

They were to be his last words. Moments later, Shackleton suffered a fatal heart attack. Frank Wild – Shackleton’s right-hand man – recorded his conversation with Macklin immediately after he left the great explorer’s cabin: ‘I sat up saying, “Go on with it, let me have it, straight out!” Macklin replied, “The Boss is dead!” It was a staggering blow.’

At the request of his wife, Emily, and in keeping with Shackleton’s own desire to be among the craggy, inhospitable landscape that had meant so much to him, Shackleton was buried at the whaling station of Grytviken, South Georgia, facing south towards the Antarctic. In a wonderfully poetic final moment, Shackleton’s last diary entry read, ‘A wonderful evening. In the darkening twilight I saw a lone star hover, gem-like above the bay.’ In a fitting tribute to his lifetime love of poetry, the words of Robert Browning were inscribed on the reverse of his gravestone: ‘I hold that a man should strive to the utmost for his life’s set prize.’

Shackleton may not have achieved his life’s set prize in his lifetime, but his legacy certainly lives on. His reputation for courage in adversity and inspirational leadership is based on a bigger success: the survival and safe return of his entire crew in unimaginably difficult circumstances.