The Mosque itself is one of the largest in UK, with a capacity of up to 5000 people. It opened in 1985, and took around three years to build. The London Muslim Centre, meanwhile, is a much newer development having been constructed between 2002 and 2004, at a cost of around £10.5m.
However, the organisation dates back much longer than this, to 1910, when notable local Muslims established the London Mosque Fund to build a mosque. By 1926, the fund had grown considerably, and the first Mosque was opened in three houses on the Commercial Road, E1, in 1941.
For more details of the opening, which includes guided tours, see http://www.eastlondonmosque.org.uk/news/288