As I wrote in the recumbents page already, the diamond frame based bicycle were formerly known as "safty bicycle",
as the common bicycles in 1880's were having a huge tail wheel (aka Higher Wheeler or Penny Farthing) which posed security risks due high fall height.
John Kemp Starley then invented the safety bicycle, today also known as diamond frame bicycle - or these days also known as the common or ordinary bicycle.
Due the primary shape of the frame it is labeled as Diamond Frame or DF bicycle.
Draisine by Karl von Drais (1817)
High Wheeler aka Penny Farthing (~1870)
John Kemp Starley's Safety Bicycle (1885)
In 1934 the world cyclist organization UCI banned the
recumbents and kept sticking with the Starley's "safety bicycle" of 1885, and still does.
By this ban the recumbents were out of all "cycling" competition UCI ruled, which made a significant dent in the further development of bicycles itself, and recumbents in particular.
More history at
Bicycle History .
.:.