Geographers have put together models of land use to show how a 'typical' city is laid out. One of the most famous of these is the Burgess or concentric zone model.
This model is based on the idea that land values are highest in the centre of a town or city. This is because competition is high in the central parts of the settlement. This leads to high-rise, high-density buildings being found near the Central Business District (CBD), with low-density, sparse developments on the edge of the town or city.
However, London is better represented by the Hoyt model. This is based on the circles in the Burgess model, but adds sectors of similar land uses concentrated in parts of the city. Notice how some zones, eg the factory/industry zone, radiate out from the CBD. This is usually following the line of a main road or a railway.
In London, the River Thames became central to industry. Therefore, working class housing was developed along the river, moving eastwards from the CBD.