From the accompanying article in The Guardian;

"The visualisation, originally created for the Almost Lost exhibition by the Bartlett Centre for Advanced Spatial Analysis (Casa), explores the development of the city through the evolution of the road network and preserved buildings."

"The animation took nine months to make, using a variety of methods and data from several sources. The Museum of London Archaeology provided datasets for the Roman and Medieval periods as well as the 17th and early 18th centuries. The University of Cambridge’s engineering department contributed road network datasets from the late 18th century to today. An additional Tudor layer was based on a map of London in 1520 from the Historic Towns Trust; data on the city’s 19,000 listed buildings and 156 scheduled monuments came from English Heritage; and buildings data was drawn from the Ordnance Survey.

In the visualisation, new road segments appear gradually over an image of faded contemporary London. For each period, gradually enlarging yellow points highlight statutorily protected buildings and structures."

One thing I hadn't realised until I read the article was that London's population reached its peak of 8.5 million people in 1940. It dropped sharply after that and has been steadily rising again for some time but is still only 8 million or so.

That was very good.

And this one illustrates in simple graphic form the evolution of the tube system from its beginning up to 2012.