Tube map pioneer Harry Beck will today have his iconic creation officially commemorated on the 80th anniversary of its first public appearance.
An English Heritage Blue Plaque will be unveiled at Mr Beck's birthplace in Wesley Road, Leyton, east London.
Early Tube maps had proved fairly unsuccessful, with creators' concern with geography and distance between stations leading to squiggly hard-to-work-out guides to stations.
Mr Beck's map was different in that it ignored much of what had gone before, favouring, instead, an easy-to-follow grid system on which all subsequent maps on an expanding network have been based.
For instance, Mr Beck worked out that people did not really need to know the distance between stops so much as what the next station would be.
The plaque will be unveiled by London Transport Museum Director Sam Mullins who said: "Beck's map was revolutionary in its simplicity.
"It has become a London icon and influenced the design of many Metro maps across the globe, as well as being the inspiration for many contemporary artists and designers."
Mr Beck, who had started work with London Transport as an engineering draughtsman, was supposed to have been paid just five guineas (£5.25) for the original design.
He died, aged 72, in 1974.