The Notting Hill Carnival is back in full swing, as London celebrates the impact of its Caribbean heritage, but not all are there to celebrate.

The Notting Hill Carnival is one of the world’s largest celebrations of Caribbean music and culture, an annual event in West London ach August.

After the end of WWII, Britain’s government encouraged mass migration from the countries of the wider Commonwealth to fill their depleted labor market, giving citizenship to all people from any U.K. colony. This resulted in a massive increase of Afro-Caribbean immigration to the U.K., mostly London. In the late 1950s, right-wing movement stirred up sentiment against these invited immigrants with a “Keep Britain White” campaign. A number of race riots happened, including a large on in Notting Hill in August of 1958. A white woman married to a Jamaican man was assaulted by a gang of white teenagers, and that night, a mob of 300-400 white men and women began attacking the homes of West Indian residents of the area. 108 people were charged, particularly the youths who began the violence.

The next year, Trinidadian activist and newspaper editor Claudia Jones organized a “Caribbean Carnival” at St. Pancras Town Hall, featuring music and food from the islands. It evolved into the Notting Hill Carnival a few years later, when it merged with other outdoor events and took to the streets.

This year, in its three-day run, 2 million people came from around the world to engage in its rich cabaret style celebration. It took 40,000 volunteers to run it. And unfortunately, it required 9,000 police.

Since the 1980s, the Notting Hill Carnival has gotten a reputation for violence. Since 1987, there have been six deaths connected to the festival. This year, eight men were injured in stabbings and over 300 were arrested. There is talk of removing the event from Notting Hill to somewhere easier to police in the future, but much opposition.