The Ferguson Model TE20 was a British

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 agricultural tractor

Tractor

A tractor is a vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction...

. It was Harry Ferguson

Harry Ferguson

Henry George "Harry" Ferguson was an Irish engineer and inventor who is noted for his role in the development of the modern agricultural tractor, for becoming the first Irishman to build and fly his own aeroplane, and for developing the first four-wheel drive Formula One car, the Ferguson P99...

's most successful design, commonly known as the Little Grey Fergie. It was manufactured from 1946 to 1956. It was a light weight but effective design and is a popular collectors item for enthusiasts today.
The model name came from Tractor, England 20 horsepower (not the true power delivered but from a formula based on engine size, see tax horsepower

Tax horsepower

The tax horsepower or taxable horsepower was an early system by which taxation rates for automobiles were reckoned in some European countries, such as Britain, Belgium, Germany, France, and Italy; some US states like Illinois charged license plate purchase and renewal fees for passenger...

).

The TE range of Ferguson tractors were introduced in England in 1946 following 30 years of continuous development of 'The Ferguson System' from 1916.