On a wet, blustery March evening in 2009, two neo-Nazi boneheads were on a train to Welling in south east London, wearing Dr. Martens, combat trousers and bomber jackets. They were on their way to a Nazi-punk show organised by the Blood & Honour music network.

As the pair disembarked the train, they discovered a mob of 40 militant anti-fascists waiting for them on the platform. One shouted "Kill the Nazis", and the mob attacked. One of the duo was beaten to the floor and set upon, while the other was chased onto the railway tracks by an anti-fascist skinhead singing "Antifa hooligans" by Los Fastidios, an Italian Oi! band.

The anti-fascists were from a group called Antifa, set up in the UK in 2004, well before the term "antifa" became part of the lingua franca of the current Trumpian nightmare world.

Antifa activists group up at Welling Station earlier in the day (Footage taken from British Transport Police CCTV)

Since fascists first emerged in the UK, anti-fascists have been organising against them. Antifa was an attempt by anarchists to keep militant anti-fascism alive in the UK. Founded in a rickety old room in east London, the group drew inspiration from the European antifa groups British anti-fascists had come into contact with through the anti-globalisation movement and the punk scene.

One of Antifa's founders, Ciarán, told me: "There needed to be a militant anti-fascist group on the streets again, and we looked at the rest of Europe and saw the antifa groups. They had the common tactics – either all black bloc types, all mainly anarchist – and we thought we'd lump in with them and we'd create an English version of the existing European antifa organisations, so that's what we did."

But the Antifa group in England wasn't to last, disappearing nearly a decade before their name became the favourite Google search term of angry right-wing Americans. Still, they managed to get a fair bit done before their time was up.

Antifa activists walking through Welling (Footage taken from British Transport Police CCTV)

In 2004, the BNP won 808,200 votes in the European Parliament elections, making it the most successful fascist political party in British history at the time. The BNP had led the far-right off the streets and onto the doorstep, which meant political street activity was limited. Opposing the BNP’s electoral campaigning was difficult, but Antifa still had a go.

One former member – Rob, from north London, who was in Antifa in his late teens – told me about an incident where they attacked a BNP meeting: "We got a tip off about a BNP election meeting up in Yorkshire, so a group of us from London rented a minibus and drove for god knows how long to meet up with some of the Yorkshire lot to go and disrupt it."

Rob continued: "On the way we loaded the van with bricks and bottles, and once we met up with the local Antifa there were about 40-odd of us. We rolled up to where they were having their meeting and everyone got out of the vans – except for the drivers, obviously – and the two guys on security duty ran inside and bolted the door while we set about smashing up their cars. Windscreens, windows, mirrors all got smashed. One of the Yorkshire guys ran out of rocks and punched one of the windows through with his bare fist. Cut his hand a bit, but he was alright. Someone blew a whistle and, as agreed, we all piled back into the vans."

Antifa activists walking through Welling as night falls (Footage taken from British Transport Police CCTV)

The majority of Antifa's activity involved targeting far-right activists before or after their protests, which were too heavily policed for militant anti-fascists to get close to. Dressed in casual clothes so they could blend in with normal people – rather than the black bloc style which has become increasingly common – Antifa activists would wait around transport hubs for the far-right to arrive.

Rob told me about an occasion when they were looking for National Front (NF) activists on their way to a protest in South London: "We saw two of them – big bald-headed guys in black bomber jackets, black combat trousers and black boots. We followed them onto their train. One of our lot went and asked if they were going on the NF march, to which they responded enthusiastically. The guy in front of me hit one of them with an upper-cut so hard that the NF guy's head flew back into the glass train panel with a bang.

"While he was scuffling with two of our lot on the platform I went up and booted him as hard as I could in his ribs, and landed some punches on his head, while the others were trying to drag his mate off the train. For all his hard-man look he was trying his best to abandon his mate, and just got battered on the train. As we were scattering, the first NF guy picked himself up off the floor and walked over to my mate, punch-drunk and staggering, [and said], 'You want some!' So my mate walked over to him, landed two big punches on him and left him on the platform. Fuck knows what state they were in when they reached their demo."

Antifa activists group up at Welling Station earlier in the day (Footage taken from British Transport Police CCTV)

Antifa grew from a handful of small groups in the South East and Yorkshire to a network across England, with factions in London, Leeds, Nottingham, Birmingham, Brighton, Essex, Bristol, Portsmouth and Plymouth. Shortly before the network folded there were groups "popping up everywhere", according to Ciarán, who was the national organiser for the network when it ended. Antifa was also building links with groups in Europe, sending delegations to take part in anti-fascist protests in Germany, Czech Republic and Poland.

The group didn’t just target the far-right’s meetings and protests; Antifa had a strategy of identifying key organisers and then pressuring them to leave active politics.

I spoke to Ryan, from the north of England, who was a young member of Antifa. He explained that these tactics were largely borrowed from the animal rights movement and involved threats and property damage. On one occasion, Ryan took part in an action against the BNP's Red White and Blue (RWB) festival. He and some others visited the farm where the festival was being held, vandalised buildings and vehicles, padlocked the gates shut and stole a large England flag.

In August of 2008 Antifa organised against the festival, bussing in people from across the UK to rural Derbyshire. Over 100 militant anti-fascists tried to shut down the event, but were stopped by riot police. Ryan explained that this led to a "mass brawl with police over several fields", which was condemned by The Guardian. "A group that had previously operated in a clandestine and targeted manner showed it was capable of organising large-scale public disorder," said Ryan. "I find it incredible there were not serious charges following the incident, all of which was caught on film by a police drone or helicopter."

Ryan credits Antifa's activity against the RWB festival as being the spark for the police cracking down on the group.

Antifa activists group up at Welling Station earlier in the day (Footage taken from British Transport Police CCTV)

Having attacked the two neo-Nazis on the train platform in Welling, the anti-fascists started to disperse – but not before several riot vans had arrived. Six activists were arrested on the scene, and several months later there were dawn raids across the country. Ryan believes the police had been planning a crackdown well in advance, and later discovered that he had been followed by police during a visit to Leeds in early 2009.

Ryan explained: "As a group, we underestimated the level of intelligence the police had on us, and the resources they had to monitor political activists. Despite us having what we thought of as a good security culture, some members were being closely watched – and even followed – by police in early 2009, and one member of the group – Mark Kennedy – was a serving police officer. The amount of intelligence they had gathered on us was made obvious when they raided dozens of addresses across the country simultaneously. One person had moved house only a few days before being arrested, and the police got him at his new address."

Detective Chief Inspector Sam Blackburn, from the British Transport Police (BTP), was the senior investigating officer for the investigation into the Welling incident. He told me that his work started the day after the attack, but that he ran into a problem when the two neo-Nazis who had been attacked refused to press charges. "We went to the pub [hosting the Blood & Honour concert] and identified the victims of the assault – they had quite visible injuries," he said. "They were unwilling to support the police due to their political persuasion."

This meant BTP had to rely on tracking Antifa through CCTV footage. They were able to trace the group who'd carried out the attack all the way back to a left-wing protest march against the G20 in central London earlier that day, and realised the group had been marching with a black-bloc and had been photographed by the Met Police's forward intelligence teams.

"We then started looking at the CCTV, identifying individuals through previous images that were held on those individuals," said Blackburn. "Then a lot of phone work was done in relation to the individuals, linking them to other individuals, text messages as well. They were quite hard to identify, tracking the group back, looking at similar clothing, specific things on the clothing which we could identify in the CCTV. Took a long long time, that did; we didn't have too many staff on it."

By the end of that process, police had enough on the group to get warrants for the raids. These uncovered more evidence, which investigators were able to use to build the case against Antifa.

Several months after Welling, on the 29th of July, 2009, BTP arrested around 30 people in raids involving hundreds of officers. More than a dozen of those arrested were to face trial for "conspiracy to commit violent disorder", an offence with a maximum sentence of five years. Key organisers of Antifa were among those picked up in the raids, although many of those arrested had no involvement in the Welling incident. By arresting so many suspected members, the police largely stopped the network from functioning. The bail conditions given to the arrested members made it very difficult for them to continue political activity. "A large number of arrests and restrictive bail conditions took the most active members off the streets, and those groups which escaped mostly unscathed understandably kept their heads down in the aftermath," Ryan explained. "I was banned from the entire national rail network, several London boroughs, couldn't appear in public with more than two other people, was banned from attending any preplanned gathering and wasn't allowed out of the house between 7PM and 7AM."

Antifa activists group up at Welling Station earlier in the day (Footage taken from British Transport Police CCTV)

By the end of the 2009, according to Ryan, the group folded: "A small group of delegates met secretly in Nottingham in late 2009 and agreed to formally dissolve the group," he said. "By this time the group was basically defunct anyway. Severe precautions were taken to keep the meeting secret and, as far as I am aware, the police did not pick up on the meeting. Several people attending broke their bail conditions to attend."

The main priority for activists involved in the network became supporting activists as they began to face trials, which started in 2011. The first saw six anti-fascists jailed for 21 months. The second saw nine anti-fascists acquitted. Ciarán was one of the six Antifa activists jailed for the Welling incident. "We all got sent to Wormwood Scrubs to begin with," he told me. "We were alright for about the first month, and then they split us all up and sent us off to different prisons around the country, and that was that. Really, I think that was that for Antifa as a group. It didn't, as far as I know, do actions while we were in prison – didn't do anything afterwards at all. It kind of took the wind out of our sails and, I mean, I personally came out of prison thinking, 'I can't get involved in any more activity.'"

But this wasn't the end of militant anti-fascism in the UK. Around the same time Antifa was being shut down, the English Defence League (EDL) was emerging onto Britain’s streets. Meanwhile, militant anti-fascists – including some veterans of Antifa – founded the Anti-Fascist Network (AFN).

Since then, confrontations between fascists and anti-fascists have been characterised more by pitched battles on large demonstrations, often broken up by baton-wielding riot-cops, rather than fighting on dark side streets. Anti-fascists have also put a focus on community organising against the far-right, because that’s a better way to avoid jail.

But whatever the state does to try to stop militant anti-fascists, and whether or not they remain a poorly understood staple of the public conversation, so long as there are Nazis, anti-fascists will organise against them.