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.
Daimler Company
A significant element of Daimler production was bus chassis, mostly for double deckers. Daimler had been interested in the commercial vehicle market from 1904. In 1906 it produced, using the "Auto-Mixte" patents of Belgian Henri Pieper, a petrol-electric vehicle and on 23 May 1906 registered Gearless Motor Omnibus Co. Limited. It was too heavy. Following the introduction of Daimler-Knight sleeve-valve engines re-designed for Daimler by Dr Frederick Lanchester Lanchester also refined the Gearless design and it re-emerged in 1910 as the KPL (Knight-Pieper-Lanchester) omnibus, an advanced integral petrol electric hybrid. The KPL bus had four-wheel brakes and steel unitary body/chassis construction. Failure to produce the KPL set bus design back twenty years.