For someone who spends a lot of my time sitting in traffic jams staring out of the cab’s window, I often find myself discovering blue plaques and wondering who the commemorated person might be.

I know the subject of the first blue plaque, Lord Byron. It was unveiled at 24 Holles Street; Cavendish Square in 1867 demolished in 1889. I know London’s earliest surviving blue plaque Napoleon III on King Street.

[B]ut just who was Arthur Henry War Sax Rohmer, apparently the creator of Dr. Fu Manchu or Francis Pettit Smith inventor of the screw propeller?

The most important blue plaque at 16 Eaton Place, Belgravia commemorates a gentleman unknown to most: William Ewart, MP who lived here from 1830 to 1838.

Ewart apparently was a social reformer who was responsible for the Act that introduced public libraries. It was he who in 1863 proposed to the House of Commons that a scheme to commemorate worthy citizens. Probably because Members of the House had visions of themselves remembered for posterity the scheme was swiftly adopted.

English Heritage now decides the worthy recipients. While the City of London has, as with many things, not adopted the scheme and has just one blue plaque in Gough Square depicting Dr. Johnson.

Today London has more than 880 with some incongruous couplings: Jimi Hendrix and George Frideric Handel share the same wall. Next year scheme finds itself in rude health and on the cusp of its 150th anniversary. A Blue Plaques programme celebrating this major milestone in the history of the scheme launches next year.

Photos: Former home of William Ewart in Eaton Place by Basher Eyre (CC BY-SA 2.0); Blue Plaque William Ewart 1798-1869 reformer lived here by Spudgun67 (CC BY-SA-4.0)