New ArcGIS background map of London

If you follow THIS LINK you'll be taken to an alternative map background for your maps which is an OS map of 1890s London.
You can zoom down to a high resolution and compare with the imagery of the city, and then build a map on top of the vintage mapping.
Thanks to Jason Sawle for the tipoff to this new opportunity for historic mapping.

OS C1890's historic map of London now available in ArcGIS Online thanks to @natlibscotmaps http://t.co/SdMpEhp6l3 pic.twitter.com/iZclbEpWuI
— Jason Sawle (@GIS4Schools) May 22, 2014

Here's the area around Mary Ward House near Euston for example...