Picture the scene. A ferocious gun battle is taking place in London. About 200 policemen and the Scots Guards are shooting it out with a gang of robber-revolutionaries who have killed four policemen over the previous two years.
As the bullets fly, Theresa May totters down to see what's going on, declares it "extremely interesting" and, taking control of the operation, calls in the artillery while shrapnel whizzes round her head.
It's an extraordinary image, but that is essentially what happened on 3 January 1911, when Winston Churchill, then home secretary, began directing events at the Siege of Sidney Street, apocryphally taking a bullet through his top hat. The distinctive, fur-lined greatcoat that he wore that day, as seen on the Pathé newsreel shown in cinemas that evening, is one of the items in the "London Under Siege" centenary exhibition at the Museum of London Docklands, which does an excellent job of unpicking the complexities of this lurid, fascinating affair.
The siege capped a triptych of dramatic events that began with the "Tottenham Outrage" in January 1909. This was an "expropriation", or wage snatch, carried out by two Latvian refugees and interrupted by the police. During a two-hour chase - in which the heavily armed robbers hijacked a tram - a policeman and a boy were killed. The Latvians shot themselves rather than surrender.
Such casual disregard for human life provoked a wave of anti-immigration protest. The Latvians were from a group of revolutionaries, mostly anarchists, who fled Russia after the 1905 uprising and settled in London. Like the Angry Brigade 60 years later, they used numerous aliases and engaged in criminal activity to finance their politics. This proved to be their undoing.
In December 1910, the gang staged another robbery. It rented apartments in a building backing on to the jeweller H S Harris, at 119 Houndsditch. The intention was to break in and crack the safe, but the robbers were overheard and the police were called. The Latvians came out shooting and three unarmed City of London policemen were killed, along with a robber downed by friendly fire.
Once more, London was outraged and the newspaper headlines captured the public fury against gun-toting "aliens", Seven hundred and fifty thousand people lined the streets around St Paul's for the policemen's funeral procession. The exhibition features some of the sophisticated guns used in the robbery - quite how these impoverished immigrants got hold of such weapons has never been discerned - and a gorgeous, wooden model of the crime scene made for the trial of five (acquitted) Latvians, as well as newsreels, oral history, photographs and posters.
But the drama was not over. The gang - including, it was believed, its enigmatic leader, Peter the Painter - was traced to 100 Sidney Street in Stepney. Again, a gunfight broke out. The siege became a public event as cabs from a special rank at Aldgate rushed people to the location, where residents rented rooftop seats for ten shillings. As the battle intensified, a cat and dog were killed in the crossfire. Churchill called in the artillery, but before it could arrive the building caught fire. Churchill would not let the fire brigade put out the flames.
Two bodies were recovered and identified as Fritz Svaars and Josef Sokolow. Of Peter the Painter, there was no sign. It was said that he had escaped dressed as a woman and a poster offering £500 for his capture was around as late as 22 January. Peter has recently been named as Janis Zhaklis, a Latvian anarchist who disappeared in 1911.
One of the most remarkable things about the siege is how little impact it had. A new medal for police bravery was introduced but the Liberal government ignored knee-jerk demands from the right-wing press to restrict immigration or arm the police and merely placed the remaining Latvians under stringent observation, which seemed to do the job. Indeed, the siege's greatest legacy could be the commemorative plaques on nearby housing blocks - Peter House and Painter House - which were still attracting the impotent ire of the Daily Mail almost 100 years later. l