Double-decker bus
The first commercial horse-drawn double-decker omnibuses were introduced in England in 1847 by Adams & Co. of Fairfield, Bow, then improved upon by John Greenwood, who introduced a new double-decker in 1852.
Hyderabad Allwyn
The first double-decker buses in Hyderabad were introduced in April 1963. These buses were designed by Hyderabad Allwyn Limited with APSRTC . Eventually the Coach building division became one of the largest coach building contractors for the Andhra Pradesh government's state operated APSRTC buses. Allwyn also built the Indian Army's medium-capacity Shaktiman truck bodies which were originally designed by MAN, Germany as the 415 L1 AR truck.