On the afternoon of 10 April 1981, 20 years ago, the Brixton riots began. "Riots" is not really the right word: this was an insurrection against the British police. From Brixton the riots snaked their way to other parts of London, including Peckham, Southall, Wood Green, Finsbury Park, Woolwich, Forest Gate and Notting Hill; to Liverpool, Birkenhead, Sheffield, Manchester, Leeds, Hull, Newcastle and Preston in the north of England; to Coventry, Leicester, Derby, Birmingham and Nottingham in the Midlands. And the south was affected, too: Southampton, Cirencester, High Wycombe, Gloucester, Luton, Reading, Aldershot and Cardiff. All saw riots between 10 April and 23 July.

Brixton was different then. With the Victoria Line still relatively new, it was not quite the open community it is now. It was, in some respects, a quiet village. The musicality of the area was part of its charm. Warm spring days marked the beginning of a street culture. But, for the first time, the Caribbean community could boast a generation of school leavers. They had attended the same schools as whites, eaten the same school dinners, spoke the same language, and so on. But at the end of their schooling, they saw that the whites got jobs, mainly as apprentices in the public utilities; they, the blacks, got none.

Over the course of the 1970s, these young black men and women would increasingly gather in large numbers and display a hitherto unknown confidence. They were targeted by the police, mainly through stop and search. This led to several skirmishes and eventually to more brutal clashes. I remember witnessing one from a distance of about four yards at the Metro Youth Club in Notting Hill. One minute there was just pushing, shoving and shouting. Then suddenly there came a violent eruption. Blood was everywhere. The temper of that evening told me that something mighty was on the social agenda.

I lived in Mayall Road, in the heart of black Brixton. I worked out of offices on nearby Railton Road, where a group of us published Race Today. We had five full-time staff, and we doubled as an advice centre. Always, always there were running commentaries on police brutality and other malpractices. There was a group of four or five officers whose names tripped easily off the tongue. They provoked several skirmishes, particularly at weekends. They walked in pairs. They would provoke a stop and search and then a mini-explosion. Their presence was like red flags to bulls.

Then came Operation Swamp. I know not whose idea it was. It began in the week ending 11 April. I was stopped and searched every single day of that week. If you were black and male, you were under the power of the police. Young white boys in plain clothes, they literally swamped the area and stopped anything black that moved.

On the Friday, two officers stopped me and I refused to be searched. I was only yards from my office and I did not see how, since I had not spoken to or touched anybody, it could reasonably be thought that I had committed an offence in that short distance. I was prepared to use force to stave off the police. I started on a rant and a rave, addressing a gathering of young men and telling them about their rights surrounding stop and search. It became part of folklore at Brixton police station - as an ex-officer who now lives on the Isle of Skye told me the other day - that I had upped the ante.

Next day, a band of police attempted to stop and search a group of blacks. In no time, about 30 young men gathered and began planning a huge insurrection. Forces poured in from other parts of south London to perform under the command of those 30 or so who had lifelong knowledge of the terrain. Police reinforcements also arrived, but they did not know Brixton - nor did they have the weaponry to stave off the violent nature of the revolt.

All history gelled that day. Anger that had been stored up in the black community over the years suddenly exploded. After three days, the young blacks left Brixton a desert. There has been nothing like it before or since.