Closer look at street gangs

Clearly, the most contested boroughs, or those with most gangs, appear to be Hackney, Newham, Waltham Forest (all east London), parts of south London - most notably Lambeth and Southwark, Enfield, Haringey and Islington in north London and parts of west and north west London borders (Brent & Westminster).

The shaded areas represent boroughs with the highest volumes of youth violence. Those represented by the darkest shade have the highest volumes of youth violence, unsurprisingly Lambeth, Southwark and Newham although more surprising is that Enfield is amongst the top.

Boroughs represented by the lightest shades have very low volumes of youth violence, they include Bexley, Hounslow, Kingston upon Thames, Richmond upon Thames and Sutton.

Some of London's Most Widely Known, Reputed, or Publicised, Gangs

Below is a list of some of London's largest, most publicised, and most widely known gangs by area of London (NB this is not definitive, the gangs with the greatest reputations on the streets are not all subject to mass media attention like some of those listed below):

East London (E1-E18):

• 925 - Hackney, a combination of some historic gang areas situated throughout E9 and E5 (9-2-5) such as Ballance Road to Well Street and the Pembury estate.
• Beaumont Crew (Base) - One of Waltham Forest's most reputed and longest established gangs going back to the 1990's, older generations have been responsible for a handful of murders in London as well as armed robberies and large scale drug distribution. The younger generation lives on through an alliance with several other local gangs. A veteran member of the gang, aged 33, was recently sentenced for the killing of a rival gang boss. 
• Holly Street Boys - Hackney, a long history going back decades, best known for their long-standing rivalry with neighbouring London Fields Boys.
• London Fields Boys -Hackney, one of London's most reputed gangs for over a decade. LFB have been implicated in several murders, most recently that of a 16-year-old girl in Hoxton, whilst older generations have established links with criminals all over London (like many gangs listed here above and below).

There are numerous other gangs of note in east London, predominantly in Hackney although the once tight-lipped criminal underworld of Newham has began to harbour a host of street gangs. Newham has become one of London's highest crime boroughs for robbery and serious violence in recent years.

North London (N1-N22):

• Love of Money (and now Hoxton), Hackney, developed from one of London's oldest street gangs beginning in the 1980's. 
• Tottenham, Haringey, has long been the most reputed gang area of north London beginning with the 'Broadwater Farm Posse' on the Farm (Broadwater Farm) from as far back as the late 1970's. This area has gone through multiple manifestations since with the infamous Tottenham Mandem to todays BWF (Broadwater Farm) gang.
• Wood Green MOB, Haringey, is arguably one of the largest north London gangs in terms of membership with multiple generations going by various names (sets or cliques) for over a decade. Well regarded rapper G-Money hails from Wood Green. He was given an ASBO, that some may argue infringed on his human rights, that amongst other things restricts his expression through music. Despite the ASBO he continues to make popular 'road music' (see Back Now music video and note disclaimer "WARNING WE DONT PROMOTE VIOLENCE WE JUST MAKE GOOD MUSIC). 

North West London (NW1-NW11):

The vast majority of most well renowned North West London gangs are located in the borough of Brent and include the Suspect Gang and South Kilburn gangs with their rivals from the SMG Bloods alliance, most notably Kensal Green Bloods.

Other North West London gangs worth mentioning are the QC Bloods from Queen's Crescent in the borough of Camden who are arguably the borough's most dominant gang currently.

South London (SE1-SE28 and SW1-SW20):

• The once dominant Ghetto Boys, Lewisham, and their follow on generations such as 'Shower' have been responsible for a dozen murders in London since the late 1990's.
• Peckham Boys, Southwark, without a doubt one of the most infamous, most reputed and most dangerous gangs in the whole of London even despite recent internal difficulties.
• The Stick'em Up Kids, a follow on from the once infamous Junction Boys, are one of the largest gangs in south London covering much of Wandsworth.

The London Borough of Lambeth has long been one of the most, and often the most, violent London boroughs with the highest number of murder cases in the last decade. Lambeth often takes credit for birthing the generation of London gang 'Colours' with homegrown Blood and Crip influenced gangs alongside the likes of 'Organised Crime' and newer manifestation 'Gas Gang'.

West London (W1-W14):

West London is often forgotten about with its criminal gangs often moving more quietly. The MDP generations (Murder Dem Pussies), however, were at one point one of the most widely known gangs in London, hailing from across Ealing and Hammersmith & Fulham, the gang and its associates were responsible for several murders in the space of just a few years in the mid-2000's. Today in west London it is the Mozart Bloods (named after an estate) that have been attracting local headlines through their conflict with South Kilburn which claimed two young lives in recent years.
  http://gangsinlondon.blogspot.com/2011/08/mapping-gang-rivalries-alliances-list.html