Often dressed in a three-piece suit and tie he could easily have been taken for a businessman or a member of one of the professions.

However, Billy Fullerton was no white-collar office worker.

He was leader of the notorious 'Bridgeton Billy Boys' and their reign of terror in the 1920s and 30s left Glasgow gripped by fear.

The savagery meted out by the 500-strong mob that he ruled with an iron fist matched anything dreamed up by the producers of the violent BBC gang drama Peaky Blinders.

Fullerton's power base was in Bridgeton in the East End from where his gang took its name.

Then it was a hotbed of sectarian tension where mass brawls, slashings and extortion were a way of life.

He is the only person who can lay claim to inspiring both a bigoted football chant and a poem by the late Edwin Morgan.

However, Fullerton was also a man of contradictions.

Despite being a staunch Protestant, his mother and wife were both Catholics.

And while he provided security for Oswald Mosley's fascist Blackshirts when they were in Glasgow, he also served his country during the Second World War in the fight against right-wing extremism.

Glasgow Times:

It is not clear if the Billy Boys - who took their name from King William of Orange - were formed by Fullerton or if he simply joined up and became their leader.

However, he made them one of the largest and most powerful organised street gangs not only in Glasgow but the whole of Britain.

They had their own flute band, they wore uniforms and even marched to street fights with their main rivals.

They would conduct regular Orange parades through hostile areas of the east and Southside of Glasgow, which would predictably end in a riot.

Wars raged for two decades with Catholic gangs such as the Kent Star, Norman Conks, the San Toy and the Calton Entry.

The sectarian rivals fought with a terrifying arsenal of deadly weapons.

They included hatchets, swords, machetes, knives, bottles, sharpened combs, bicycle chains and even lengths of rope with heavy bolts attached, not unlike the South American bolas.

But the weapon of choice was the open razor.

Light, easily concealed and lethal, it earned these roaming gangs of thugs their terrifying soubriquet - the 'razor gangs'.

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Under his command, the Billy Boys were drilled with almost military precision.

Their signature tune was The Billy Boys, an infamous sectarian tribute to both William of Orange and Fullerton.

Glasgow Times:

Drilled with near-military efficiency, after meetings they would stand in all weathers at Bridgeton Cross and play God Save The King. 

On Catholic holy days, they would form a flute and drum band and march down nearby Norman Street - home to the Catholic Norman Conks gang - playing sectarian songs to wind up their bitter rivals.

They in turn would pelt the parade with stones, broken glass and human waste from tenement windows.

At one Billy Boys wedding in 1926, the groom stood before the minister with a sword concealed in his morning suit, while the best man had a gun in his pocket and Fullerton wore a bloodstained bandage on his head. 

Being in a gang was seen as the only way to defend your area, your religion and your political beliefs.  

It was also a release from the harsh realities of life in general. 

At the time poverty and unemployment was endemic in the East End of Glasgow.

However, gang membership gave a sense of belonging and self-respect on the unemployed and organised violence provided an antidote to boredom and deprivation.

The Billy Boys would fight with equal enthusiasm against teams of specially recruited police officers led by Glasgow's chief constable, Sir Percy Sillitoe.

Dubbed the 'Hammer of the Gangs', he met force with force in a bid to stamp them out.

At the time Fullerton tried to portray himself as a Robin Hood figure who would look after the wives and children of jailed members and pay their fines.

In reality, the Billy Boys were organised criminals who preyed on the communities they claimed to protect.

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They extorted money from shopkeepers, publicans and bookmakers, amassing a fortune as a result.

Jewish traders around Bridgeton Cross in the 1930s complained they were singled out for particularly harsh treatment on the basis of their faith.

Police at the time would tell sheriffs there was no point fining a gang member as a local shopkeeper would simply end up footing the bill.

Cinemas and dance halls were also targeted, with gang members raking in up to £20 a night - £1500 in today’s money.

Fullerton boasted his gang had up to £300 at any one time held in a bank account in Bridgeton.

His members were used to break up strikes and Communist Party meetings and on one occasion to act as bodyguards for a Tory party election candidate - in return for payments to Fullerton.

He formed his own band of Blackshirts to act as a Scottish bodyguard for the British fascist leader, Sir Oswald Mosley.

He was also the first modern gangster celebrity in Scotland.

When he sold his story to a paper in 1932, Fullerton revealed what life was like inside one of the biggest criminal organisations in Britain.

He had just been released from Barlinnie prison after a conviction for his involvement in yet another gangland battle.

Fullerton claimed he was trying to go straight and leave his lawless past behind because of fears for the safety of his wife and family.

He said: "I was always pretty handy with my fists and I was in a few gang scraps shortly after I became a Billy Boy.

"A few months later, I found myself the chief of the 500 young men who formed the gang at that time.

"It meant a lot of work for me, I had to make plans for fights, look after the funds, and attend to a hundred and one other matters connected with the gang and its members.

"Each of the 500 members at that time paid a sixpence or a shilling a week. This was devoted to the fighting of our court cases.

"Shopkeepers also give willingly each week for protection against other gangs.

"I am unemployed. But I have hopes of work and, if I get a job, the first thing I will do is look for a new home in a different district - far away from the centre of the city and the gangs.

"When that happy time comes, my wife and two bairns may know peace they have never known. I want a chance for the sake of my wife and children."

When war broke out across Europe in 1939, Fullerton signed up for the Navy as a boiler cleaner. It was filthy and often dangerous work and Fullerton survived being badly burned when one blew up. 

The end of the 30s would also see the demise of razor gangs such as the Billy Boys, in no small measure to the work of Sillitoe.

After leaving the Navy, Fullerton worked at John Brown's Clydeside shipyard and as a doorman for a boxing club, but his links to the criminal underwood would not go away,

At the 1958 trial of serial killer Peter Manuel, Fullerton admitted he had sourced a handgun for a gangland contact similar to the one used by Manuel to murder three members of the Smart family.

By then, Fullerton was already a sick man. 

In 1960, terminal lung cancer was diagnosed and he died from the disease two years later, at the age of 58. 

More than 2000 people paid their respects outside his single-roomed flat.

It was said grown men wept as his coffin was carried through the streets of Bridgeton and the Gorbals.

His remains are thought to lie in an unmarked grave in Riddrie Park Cemetery in Glasgow.

After his funeral, Edwin Morgan wrote the poem King Billy, which has the lines: “King Billy, dead, from Bridgeton Cross: a memory of violence, brooding days of empty bellies.”

Recently Stephen Knight, who created Peaky Blinders, revealed he had researched Fullerton's Billy Boys for the shows and was shocked at the terrifying levels of bloody mayhem they unleashed at the time.

He added: "The truth is that in the late 20s and 30s, really the hardest gangs were in Glasgow."