In the 1840s a strange religious cult appeared in a remote part of India. Its members numbered no more than half a dozen at first. They wore garments the colour of faded leaves and devoted their lives to the worship of Nikal Seyn. To them he was nothing short of a god, and when he departed this life in 1857 it came as such a shock that one of the Nikal Seynis killed himself.
Nikal Seyn was, in fact, an Irish soldier called John Nicholson and, remarkably, the cult lived on even into the 21st century.
Nicholson himself had little time for his religious followers and often ordered them to be flogged. His family and friends back home in Lisburn would not have approved of the cult either. They were devout Christians. John's parents Alexander and Clara married at the city's cathedral in 1820. John came into the world two years later in Dublin, where Alexander was a doctor at a hospital, but the family was forced to move back to Lisburn when he contracted an illness from one of his patients and died.
Clara had five boys and two girls to support and looked to her relatives for help. Clara's brother James Weir Hogg had made a fortune in India and was now an MP in England. He paid for John to attend the Royal School Dungannon and then used his influence to get him a cadetship in the Indian Army. Over the next two decades in Asia John Nicholson would earn a reputation that not only saw him worshipped by his religious followers in India, but revered too by his British contemporaries.
As Nicholson arrived in India, the British were involved in an ill-fated intervention in Afghanistan. Nicholson's regiment was sent, literally, to hold the fort at Ghazni, but his men were overwhelmed and they were taken prisoner. He was eventually freed, but was left with a lasting hatred of Afghans after discovering the body of his brother, who was also a soldier, in the Khyber Pass.
Within a decade Nicholson left out-and-out soldiering to become a 'political'. He was put in charge of a remote frontier area of British India near the Afghan border.
Now he was a policeman, judge, tax collector, diplomat, all rolled into one. Still in his 20s, he was expected to deal with hill tribes who resented any interference with their ancient way of life. But Nicholson's very presence made a deep impression on those around him.
His was a tall, imposing figure. At 6ft 2in he was a full six inches taller than the average British soldier at the time. He had a long, black beard and rarely smiled.
"Tall, dark, and stern," said one of his contemporaries, "he looked every inch what he was, a fearless, self-reliant, fierce and masterful man, born for stormy times and stirring events."
Fierce and fearless he certainly was. On one occasion, after the offer of a reward had failed to lead to the capture of a notorious bandit, Nicholson saddled his horse and headed off to hunt him down like the sheriff in a Wild West film.
He found him in his own village, surrounded by family and supporters. Undeterred Nicholson fought with him, killed him and took his body back into town. He cut off the head and displayed it on his office desk as a warning to others.
On another occasion a jihadi attempted to kill him. He coolly reported the incident to his boss in Lahore: "Sir, I have the honour to inform you that I have just shot a man who came to kill me. Your obedient servant, John Nicholson."
When Indian troops mutinied in 1857 Nicholson led a movable column, a military force set up to chase down the rebels wherever they appeared in the Punjab. The physical demands he placed on his men and himself are staggering. On one occasion they began marching at night-time, but as the July sun rose so did the temperature and men began to die from heat and exhaustion.
At 10 in the morning the men were allowed to rest in the shade of a giant tree, but Nicholson remained mounted in the middle of the road, exposed to the sun, waiting to move on. The following morning, after an 18-hour march and little rest, Nicholson led his men into battle, defeating an enemy that had five times as many soldiers.
Nicholson prided himself on keeping an effective intelligence network.
One evening his officers were waiting for their dinner and Nicholson himself to appear, but there was no sign of either. Half an hour late Nicholson entered their tent, announcing: "I am sorry, gentlemen, to have kept you waiting for dinner, but I have been hanging your cooks."
Nicholson's spies had told him the soup had been poisoned. He told one of the cooks to eat some of it, but he refused, so a monkey was brought in and some of the soup poured down its throat. It died shortly afterwards, proof of the plot against Nicholson and his officers, and the cooks were executed.
But Nicholson's methods of dealing with civilians are bound to make us feel uneasy now. They would be paraded before him and he would use his own intuition to decide who were enemy soldiers in disguise and who were innocent, who should die and who should live.
Nor did he shrink from enforcing the perceived superiority of the European. He issued an order that no Indian was to ride by any white man. He was to dismount and salaam, bending his body in an act of subservience. However, his effectiveness as a soldier cannot be doubted and when the time came to attack Delhi, which had been occupied by rebels during what the Indians call their First War of Independence, it was Nicholson who was chosen to lead the assault.
After successfully entering the city, he urged his men on, appealing to them in the name of God and the Queen to follow him.
As he rushed on, his sword arm raised, he was shot and fatally wounded. Nicholson was buried under a slab of plain granite in a cemetery that now bears his name in Delhi. Few visit it and even those who look after it seem unaware of his remarkable story.
By the time of his death John Nicholson had become a British hero. His death was described as a national misfortune. Streets and gardens in India were named after him. Back home, his mother paid for a monument to be installed at Lisburn Cathedral, depicting the assault on Delhi.
The artist was John Henry Foley, the man who immortalised Prince Albert in his London Memorial and Daniel O'Connell in Dublin. It can be seen on the wall of the cathedral still.
The statue of Nicholson in Lisburn's Market Square was erected in 1922 on the centenary of his birth, but it was a divisive occasion. Those speaking at the grand unveiling in the year the Irish Free State came into being used him as a symbol of the defence of Empire in Ireland as well as India.
There is a second statue of Nicholson at his old school in Co Tyrone. It originally had a prominent position in Delhi, but in 1957, 10 years after Indian independence, the authorities there feared it might become the focus of nationalist resentment during the anniversary celebrations.
The headmaster of the Royal School Dungannon appealed to the Northern Ireland Ministry of Education for help in 'rescuing' it. It was shipped from Bombay and unveiled by the last Viceroy of India, Lord Mountbatten, in the school's grounds in 1960.
As for the Nikal Seynis, the cult lived on long after Nicholson's own demise. Nikal Seyn assumed the status of a Muslim saint. Stories were told of him dispensing rough justice on those who terrorised the poor. According to legend, he once mistakenly chopped off a man's head, but, realising his mistake, stuck it back on again.
Remarkably, the last of the Nikal Seynis died only in 2004. He lived in the Pakistan town of Abbottabad, a link in a remote corner of what is now Pakistan with the life of a remarkable Ulsterman 150 years after his death.
Stuart Flinders is the author of Cult 0f A Dark Hero: Nicholson Of Delhi, which is published this month by IB Tauris, priced £25