For a brief moment, at vast and lawless raves such as Castlemorton, a generation glimpsed an alternative way of life. Speaking to survivors of the early 90s free party scene, Tim Guest tells the story of how the state crushed the dream

On 19 April 1992 - Easter Sunday - Spiral Tribe, a self-described "rag-tag sound system group who came together driven by the will to keep the party going", who had been running free raves with a mobile rig across the UK since 1990, set up in a warehouse in Acton Lane, west London. To a packed house, they partied through the night. In the early hours, police officers from the Metropolitan Police's Territorial Support Group, a specialist division with duties including crowd control, surrounded the building. Those who tried to enter or leave had to face the TSG (the same group responsible for heavy-handed policing of crowds in the recent G20 demonstrations). According to witnesses at Acton Lane, some TSG were masked and had their ID numbers covered. The Spirals and partygoers barricaded the doors, but after a 10-hour stand-off, the police revved up a JCB and broke through the outer wall. Scores of ravers later alleged they were beaten in the dark of the warehouse; witnesses claim one pregnant woman was knocked to the ground. One man who tried to escape over the roof claimed to have been pushed; he fell two storeys breaking both arms and legs. No charges were brought. The next day a police helicopter escorted the Spiral Tribe convoy, 10 vehicles long, out of the London area.

Simone, one of the original Spiral Tribe members, who had fallen into the free party scene years before after working in a PA hire shop in north London, recalls: "Everyone who was there remembers exactly what happened. Being forced down on to muddy floors, being battered. It was a horrible experience.

"They were letting people in and not letting people out, then letting people out and not letting people in," she continues, talking from her current base in a Paris apartment. (Like other Spirals I talked to, she didn't want me to use her full name.) "All of a sudden you peered out of a crack in the wall, and the place was surrounded by every kind of police vehicle you can imagine. They had diggers, they were all in their riot gear, shields. We'd just been dancing for a few days, we're in the middle of an industrial estate, not really affecting anybody else around, and then all of a sudden they started bashing the wall in. They smashed up the decks, just went to town basically. Imagine people who've been up for two or three days dancing; you're a bit tripped out at this point. People were being carted off to hospital."

The Spirals were used to run-ins with the law - "we'd had lines of police directing us across fields" - but nothing like this. "At that point we realised the police were really on our case. There was a news blackout. We tried to call all the journalists we knew, and there was nothing. What happened was kind of obscene, but it went unreported. It felt like we had no way of telling anyone.

"Really, what were we doing that was so disastrously wrong? Occupying empty buildings, playing music and dancing. People of all walks of life were coming together on the dancefloor. They [the police] acted completely out of fear."

Following interim parties at Chobham Common and Stroud Common in Surrey and in the Cotswolds, where they rebuilt some of their equipment, the Spirals elected to seek refuge in numbers. Deciding, as one member recalls, "to take it easy at someone else's party for a change", they headed for the Avon free festival, a regular May bank holiday gathering near Bristol. This year, though, Avon and Somerset Police had other ideas. "They were digging trenches, no one was able to go to the site," says Simone. Police encouraged the sound systems to head towards Castlemorton Common, a few square miles of public land just east of the Malvern Hills. "At Castlemorton we had the biggest space, but our rig was not the loudest," Simone recalls. "After Acton Lane, half of our speakers were blown. But people were always offering us things to make up for lost equipment." Spiral Tribe set up in a semi-circle of trucks, with the centre stage under a huge painted spiral, and joined the party.

It was an event that would never be repeated; a brief triumph for those who wanted to party in the face of vested interests that would soon move in to crush the scene. But for that short window - four days - Castlemorton was a free festival on a new scale. Simone recalls spending some of the time hiding, in awe of the size of the gathering. "It was like, 'Oh shit, what have we done. Things are not going to be the same after this.'" Ten rigs, including Circus Warp, Circus Normal and Bedlam, Adrenaline and Nottingham's DiY sound system set up and declared their own takes on acid house, hardcore, early drum'n'bass and Detroit techno records played at double speed. An estimated 20,000 to 40,000 people gathered, brought together by the music, the freedom and the drugs: travellers, crusties, ravers and new agers - who came with dogs on strings, blue dreadlocks, shaved heads and fire-breathing kits - and just maybe David Cameron, or someone who looked a lot like him (a YouTube clip recently surfaced from Sunrise, an '88 acid house rave, showing a long-haired raver who resembles the leader of the opposition - but Conservative central office deny it is him). There was free enterprise, too, as long as you were shopping for lightsticks, whistles or Rizla.

As the ravers drummed up a party, news hounds drummed up a controversy. David Baldwin, a 37-year-old mechanic whose front garden was 20 yards from the nearest sound system, told the Daily Mail he had seen "youngsters injecting heroin in a Renault 5". Brian Clutterbuck, a smallholder in his 40s, patrolled the edge of his land with a pellet gun. Locals complained about property damage: fence posts, they said, had been ripped up for firewood, and dogs were killing sheep. The local pub and post office shut. In an echo of similar tensions two decades before, locals called the ravers "hippies".

Castlemorton was the lead story on the BBC Six O'Clock News on the Friday and Saturday nights, and the coverage drew people from across the country. (One raver remembers returning home four days later "with eyes like pandas and my mother asked, 'Did you have a good time?'" He told her he'd been at a free party. "'Yes! I know!' she replied. 'I saw you on Central News.'") People in convoys hundreds of cars long hoped those they were following knew where they were heading. Entry routes were blocked not by police but by ravers. Police helicopters flew low over the site to film, and at one point five shipping distress flares were fired at one of them. "This illustrates the lengths to which these people will go to try to prevent police access to the site," West Mercia's assistant chief constable, Philip Davies, said. "Many of them have already displayed an extremely aggressive attitude towards the police, and the safety of my officers must be one of my priorities." There were too many partygoers, in other words, for the police to shut it down.

"These people who live here shouldn't be afraid," one told the Mail. "They should join in." Another, Richard, told the Daily Express: "There is nothing wrong with what we are doing. We are here to have fun in the sun. We chose to live this way and reject the hassles associated with a conventional way of life. Some say we are dirty, but we are environmentally conscious, we make efforts not to dump rubbish. People generally have it in for us because of our lifestyle. I think many envy us because of our freedom."

In a 1970s short story anthology, Three Trips in Time and Space, three leading lights of golden age science fiction wrote of various futures where teleportation was possible. Sandwiched between two eulogies of ease and motion was a delightful dissenting voice: Flash Crowd, by Larry Niven, in which teleportation brings about a terrible anarchy, where millions wander the earth, materialising instantly wherever the latest sensation carries them, leaving destruction in their wake. This was the future that middle England seemingly feared. It was 1992: mobile communications technology had only just begun to reshape our lives (Simone recalls Spiral Tribe had one brick-sized mobile phone, which held a charge for "about three minutes - we saved the charge and we'd phone up TouchDown radio with the location of the party, which they'd announce at midnight") - yet, it seemed, crowds were already on the move.

"Castlemorton was scarily conspicuous," says Sebastian, another Spiral Tribe member. "You had this sense of, well, what's going to happen next."

Castlemorton didn't just teleport out of nowhere: the rise of the free party scene had been a long time coming. In 1981, Joe Rush, a 21-year-old punk living in Ladbroke Grove, joined the Peace Convoy, a rotating caravan of, he says, "around 40 dodgy and illegal trucks, cars, vans and old ambulances" that roved England from the Windsor and Glastonbury free festivals to smaller parties on common land. In the early days the convoy developed its own tactics to use against the police and local authorities: once, after being refused at a service station, they blocked a three-lane motorway and slow-rolled until police relented and allowed them to refuel. Later, the police response grew brutal, culminating in the Battle of the Beanfield, a police action in June 1985, at the intended 14th Stonehenge free festival. One thousand officers - again with their numbers covered - smashed 140 vehicles and beat the travellers, after which, Joe says, the heart went out of the Peace Convoy.

Rush, who later co-founded the Mutoid Waste Company sound system, traces the heritage of the Peace Convoy back to Ken Kesey's Magic Bus Trips and Acid Tours in 60s America, as well as to the tradition of travelling communities in this country, and also links it to political events such as the 1984-85 miners' strike. There were in fact direct connections: in 1989, chief superintendent Ken Tappenden, who had been involved in the miners' strike police action, started the Pay Party Unit, tasked with controlling the rave scene. The unit monitored pirate radio, tapped phones, and organised helicopters to track the organisers. After three months, they had begun 20 major investigations. As Matthew Collin and John Godfrey note in their book Altered State, the Pay Party Unit's database held 5,725 names and details on 712 vehicles. Within weeks, their 200 officers had monitored 4,380 telephone calls and made 258 arrests.

This was around the time Spiral Tribe's Sebastian, aged 17, moved down from west Scotland to London to play in a psychedelic band. A friend invited him to a party. "I thought it was going to be like a Scottish party, with a few friends standing around drinking. We went to Old Street station, where there were loads of police and ravers milling about. A car pulled up and took us to Clink Street." This was a maze of arched vaults on the site of Britain's first prison, near London Bridge, where DJs including the Shamen's Mr C championed the new rave sound. "That was my first rush of acid house," Sebastian says. "After that night, my life was very different." But the Pay Party Unit was working hard, and legislation followed. In 1990, MP Graham Bright introduced the Entertainments (Increased Penalties) Bill, which raised fines for throwing an unlicensed party from £2,000 to £20,000 as well as a possible six months in prison. Nicknamed by Bright "the acid house party bill", it was a clear attempt to push the free-party scene into the licensed leisure industry, so it could be regulated. "It made a difference," recalls Sebastian, speaking to me from Paris after a long weekend of DJing in the French countryside. "The parties changed. Everything had gone into a more clubby direction. I'd been educated by mad illegal raves, and the energy was so different to what I was finding after that. There was a hunger to get back to the acid house rave thing. That was the reason Spiral Tribe came about."

In October 1990 he went to the first Spiral rave, in a squatted schoolhouse in London's Kensal Rise. "I didn't have all the fancy clothes, I didn't have what was necessary to fit in to certain clubs. You walked into Spiral Tribe and none of that mattered. It was like going back to those '88 raves. People were totally friendly; they didn't judge you by what you were wearing. I was hooked."

The Spirals staged their first party in late 1990. By June 1991 they had a mobile rig, and over the next year they travelled England, announcing their integrated ethic on their flyers: "We are here to reconnect the Earth"; "We're part of the earth; we're part of us"; "You might stop the party but you can't stop the future."

This was where people of my age, in their mid- to late-teens at the time, discovered the parties. It's hard to picture those days now, before the internet, when mainstream press had a tighter control over how we saw events like this. Word reached us through friends, or from pirate radios such as TouchDown and Rush FM. At warehouses and squats, UV paint across the walls, we gathered to dance all night to pitch-shifted breakbeats that had yet to be harnessed for TV adverts. The music, impenetrable to many - like me - before their first pill, seemed uniquely British: the harsh beats and melodic breakdowns seemed to dramatise the disjoint in our lives, between life in an impersonal money-focused state, and the new easy honesty we were discovering with each other. The open spirit of those parties seemed like a gateway to a possible future. We told each other things we hadn't said before, and we told them to strangers too. Back then, even the rivalry between sound systems and police had occasional friendly moments. I remember one early morning in mid-1992 walking back through an east London park with the owners of a sound system, lugging a speaker each, as a TSG riot control van followed us. We heard the crackle of their PA system and picked up our pace, fearing arrest. "You should have borrowed our sound system!" they joked through the megaphone, then revved away.

"It was a whirlwind two years, really, but we packed a lot in," says Simone. Spiral Tribe's living arrangements were typical of the dozens of sound systems across the UK. "We were all pretty much squatting. Not everyone. Once we hit the road, we used to sleep in the truck, under the truck, take turns in sleeping. It wasn't that important really. The first parties in London were fivers in. That gave us enough money to pay the DJs a bit, print flyers for the next party and a bit of diesel for the generator. We ate vegetable curries a lot. We didn't need much, really."

Most of the sound systems worked to ensure they left little damage after their parties. "We always wanted to leave as little trace as possible," another Spiral member recalls. "After Castlemorton, we hung out until Wednesday, Thursday, clearing up, leaving the site impeccably clean. Then, as we pulled off site, the police asked us, 'Have you been at Castlemorton?' Everyone said: 'Yes,' and that was it. Everyone was nicked. Everything was impounded. They really went to town."

Simone had left for London the day before. That day there was a knock at the door, and she was arrested. "They took every scrap of paper off the wall. We had a mini-office, where we did photocopying and everything, and they took it all."

In all, 13 Spiral members were charged with public order offences. Their trial became one of the longest and most expensive cases in British legal history at the time, lasting four months and costing the taxpayer £4m. The police used any tactic they could to support their case. "We even all had our handwriting analysed," says Simone. "We had a messy office full of stuff, and they were trying to ascertain who'd written some philosophical rant. It was incredible. Actually, in the end it turned around in our favour. There was no conspiracy to bring down the government, which I think they were looking for. In the end everything was thrown back in their face, and the jury saw that. It was painful, laborious - luckily, there was a good team of lawyers, everyone had to go in every day and have their chance on the stand. Everyone was just as honest as they could be. There was nothing to hide." All 13 were acquitted. According to one witness, a superintendent approached a group of Spiral members on the steps outside the court and said: "I just want you to know that I don't agree with what is happening to you here. This is a political stitch-up."

After Castlemorton, police pressure on free parties did not relent. Some ravers believe there was an explicit agenda to extend legal licensing hours while cracking down on free parties. In that sense, superclubs such as Cream and Ministry of Sound have their direct roots in the repression of the roving sound systems. And the police tactics worked. "One weekend after Castlemorton we tried to put on a party," says Sebastian. "We had five back-up venues, and every time we arrived at the next one, the police had already closed it down. It was really difficult to put things on under the name Spiral Tribe, so it was either disband the name, or take it out to Europe. Half of the crew went to Europe, and half stayed in London."

"Where could we go?" says Simone. "They'd taken every last coin out of our pocket, impounded all our equipment - we weren't getting that back. We went to France, and it took on a new form."

There were already UK sound systems spreading across the continent. Mutoid Waste moved to Berlin, where they were when the Wall came down. With Bedlam, another sound system, they held a party by the Brandenburg Gate. Joe and the other Mutoids built a Stonehenge out of scrapped East German tanks they found in an abandoned base. After the party, and without permission, they hoisted two decommissioned MiG fighter jets on to trucks and headed further east.

"There were travellers, ravers, intellectuals," recalls Joe. "It was a crazy, mixed crowd."

"The country that really connected was France," says Sebastian. "Spiral Tribe went to Berlin, and they didn't want to know. They didn't have any need for the free party scene. Because you can go to a club all night, and the drinks aren't expensive, and the security don't get in your way."

Back in the UK, it took a few years for the law to catch up with the state's intentions to wreck the party. But when it did, it arrived with the infamous Criminal Justice and Public Order Act 1994, section 63 (1)(b), which outlawed outdoor parties. In an unusual foray by civil servants into music criticism, the wording of the act defined "music" as that which "includes sounds wholly or predominantly characterised by the emission of a succession of repetitive beats". Following the act, if there were more than 10 of you and you looked like you were waiting for a party, even if the land wasn't privately owned, you could be told to leave, and if you did not, or if you returned, you faced up to three months in prison.

Sound systems such as Spiral and Bedlam realised they could not return to the UK. They began a slow migration across Europe, sowing the seeds of rave culture, starting parties that evolved into big-name modern festivals.

In the course of the decade, the music itself took on a more central focus. In 1990, Sebastian (who still records techno under the name 69db) had commuted from a Leeds music course to London every weekend to attend Spiral Tribe parties. During the week he found himself drifting downstairs at the college to the recording studio, and making electronic music which he brought to London at the weekends. He suggested a Spiral label, and found himself handling the music and recording side of Spiral Tribe. The group had previously issued white labels, sold through friends, but through a connection with Youth from the band Killing Joke they landed a deal with Butterfly Records and a £40,000 advance for an album. "We built a recording studio into the back of a showman's trailer, and we pulled it around Europe," says Sebastian.

The French techno scene has moved towards live-performance techno. "Some live sets have gone up to 22 hours of live playing," says Sebastian. "We're mostly based in France now." These events in the French countryside attract up to 50,000 people. There the Tribe members remain, continuing to promote the cause of gathering under the banner of music, outside the commercialised system of pop. "Britain is very good at presenting music in certain ways," says Sebastian. "Ever since the Beatles, we discovered it made money. But music's a much bigger thing. It can really bring people together."

"Spiral Tribe could not now organise a festival in the UK," says Simone, referring to the likelihood that the police would find out and shut it down before it happened. According to Joe Rush, communications technology has paradoxically made it harder to arrange events outside the system. Police monitor websites, and, according to Joe, track phones. "In the old days, the police had some advantages - they had radios and we didn't. Now everyone has mobile phones. But it works both ways: it's much easier for police to track people."

Some sound systems have found a new kind of compromise. In 2001, Mutoid Waste returned to the UK. Joe Rush and co have parlayed their showmanship, honed across Europe, into events held under the name Trash City, whose giant installation shows, featuring robots, drag queens and cancan girls, are a regular feature at Glastonbury. Rush's income now comes from these events, as well as sales of his sculptures. They've come to a more reasonable understanding with the authorities. "In the Thatcher years, the battle lines were drawn," says Rush - an older punk now, with a weathered face and a worn leather jacket - in his warehouse studio in London's Old Street. "You were either one of us or one of them. It's more relaxed now. We've agreed: we have security, crowd control, health and safety ... We toughened up. We grew up. It used to be we felt everyone should be like us, but we realised we were part of society, not an alternative society." He's not alone: Bedlam have capitalised upon their expertise with easily installable sound systems into Noise Control, a successful sound system speaker business.

Nonetheless, in Britain, legislation continues to eat into our freedom to gather and party. New security regulations for live performances include a long list of prohibitive restrictions, including the need for police checks on performers. It's hard to see what motivates such control on the part of the state, except for fear. What is it about young people gathering together that provokes such a severe, sometimes brutal, response? Villages can have fetes, children can have fairs, but something about so much youth in one place scares someone. As Simone told me, "What was it that was so bad about what we were doing? We didn't leave much damage. Castlemorton is still as beautiful as it ever was."

In the tension between travelling sound systems and local landowners, it's tempting to draw grand conclusions about a schism in our nature. Joe Rush does: he sees the conflict between free parties and the state as "an age-old tension between itinerants and homesteaders". It's also tempting to romanticise the itinerant life. Who hasn't dreamed, if only in adolescence, of throwing aside commitments and living the life of the road with a surrogate family? Of course, dreams are what you wake up from, and life on the road is not all parties. Everyone I spoke to had faced problems on the road: violence, excessive drug use. Rush admits that ketamine and heroin interfered with the extrovert optimism that ecstasy had encouraged. He has a theory that the arc of a movement echoes the arc of that movement's drug of choice. "Punk was speed, an angry, dizzy rush. With ecstasy, there's a euphoric rush, then you're monged out and down. That was how things were." But the highs outweighed the lows. "The party is the best form of interaction there is," says Rush. Mutoid's solution to their troubles was to remain in motion. "We met people who were inspiring, and people who weren't," he adds. "The uninspiring people couldn't keep up." Like most of those I spoke with, Rush is still in motion. "I go wherever the work is: the UK, Japan... I live in the corner of my studio, or a friend's flat, or the back of a truck." Spiral's Simone chose the life aged 17, and she hasn't looked back. "At the time you don't really think about it. It wasn't a conscious thing. It just unfolded. I gave myself to it, which was mad, perhaps, but it's definitely been worthwhile. We put our whole selves into it."

In March, Mutoid Waste were part of Space Ritual '09, a regulated event - they appeared inside the revamped Roundhouse in Camden Town, as invited guests. Back in the winter of 1991-92, over Christmas and new year, Spiral Tribe squatted that same building. "The Roundhouse was a big shift, coming back into London and occupying such a prominent landmark," remembers Simone. She reckons 10,000 people passed through the doors. There were power cuts and door troubles, but for over a week the party went on. On that New Year's Eve, I took my first pill - a white cap and then a red and black - and, along with a group of friends, saw in 1992 from the roof of the Roundhouse. It felt like something new to all of us; a breeze from outside our regular lives. Afterwards, I went home and told my cat over and over again that I loved him.

My own circle of friends fell into the orbit of the free party movement, and we loved it, then we moved on. Seduced by secure homes and shiny cars, we made our choice. Most of us, driven by some blend of risk-avoidance and ambition, chose to remain in this world of salaries and rent payments, a life drifting in and out of our vast field of office farms. We plumped for a more widely accepted definition of freedom: we picked freedom of acquisition over freedom of movement. The world we saw from the roof of the Roundhouse was a world we loved, but not enough. You choose and you lose. But we should remember to be grateful for those who choose otherwise - especially now, when we have a drought of alternatives at the very moment we might need them.

Sebastian sees the power of free parties to foster a collective feeling as almost religiously transformative. "Day-to-day life is difficult for people," he says. "Going to work every day is all right for the few who have the job they wanted, but most people don't. And that means they're paying their taxes and paying their rent. One of the things that was good about the free party scene at the time was that you'd go out and get this incredibly good feeling from people. It's the incredible power music has."

Free party classics

Phuture, Acid Tracks

(Trax, 1987)

"Because without it, would any of this have happened?"

Bam Bam, Where's Your Child?

(Desire, 1988)

"Talk about taking it out there!"

LFO, LFO

(Warp, 1990)

"Still the prototype for bleep house."

4hero, Mr Kirk's Nightmare

(Reinforced, 1990)

"The perfect balance of acid and breakbeats."

D-Shake, Yaaah/Techno Trance

(Go Bang, 1990)

"This trancey track totally made Glastonbury 1990."

Joey Beltram, Energy Flash

(Transmat, 1990)

"Played so much it's hard to imagine the era without it."

Sweet Exorcist, Testone

(Warp, 1990)

"Another bass and bleeps tune you just can't forget."

DHS, House of God

(X-Energy, 1991)

"We spun this to death, but it never lost its allure."

Underground Resistance, The Seawolf

(World Power Alliance, 1992)

"This tune saved the acid generation and brought it all back from the brink."

Crystal Distortion, Crystal Distortion

(Network23, 1995)

"Kick-started a whole generation of artists."

• Chosen by Spiral Tribe's Sebastian, aka 69db