Blue plaques are much part of London as the pigeons. The scheme was founded in 1867 by the Royal Society of Arts but now is passed to the English Heritage who has erected over 300 plaques so far. The sign installed in a public place commemorates a link between that location and a famous person or event, serving as a historical marker.
In order to be eligible for an English Heritage blue plaque, a figure must have been dead for twenty years or have passed the centenary of their birth. Nominated figures must be considered eminent by a majority of members of their own profession; have made an outstanding contribution to human welfare or happiness; have resided in a locality for a significant period, in time or importance, within their life and work; be recognisable to the well-informed passer-by, or deserve national recognition.
If you grew up in London you certain have seen one of them on your way to work, or school, or in a summer afternoon while walking around the city.
Look up above the pavement level and the litter, above the decoratively stacked shop fronts and living room windows of the London streets, and where your see the familiar blue ceramic plaque pause for a glimpse into the life of the famous person who once "live here", behind theses walls and windows.
Blue plaques add so much to the personality of London that one wonders why there are no more of them.