The Londonist website, which has made it its mission to compile and collate alternative maps of London, has done a nice job making a medieval Tube map, using the names of places from roughly 1,000 years ago. The above is our section of the Central Line.
The map in full can be seen at the Londonist here.
1000 years ago was the Dark Ages not Medieval surely
Either/both: http://www.museumoflondon.org.uk/london-wall/whats-on/galleries/medieval/