Marshall, Sons & Co. was a British agricultural machinery manufacturer founded in 1848. The company was based in the Britannia Iron Works, Gainsborough, Lincolnshire. Early production was of steam engines and agricultural machinery. Later production included diesel tractors such as the Field Marshall, Track Marshall and former Leyland wheeled tractors.

Gainsborough is a market town, inland port and civil parish in the West Lindsey district of Lincolnshire, England. The population was 20,842 at the 2011 census, and estimated at 23,243 in 2019. It lies on the east bank of the River Trent, 18 miles (29 km) north-west of Lincoln, 16 miles (26 km) south-west of Scunthorpe, 20 miles south-east of Doncaster and 39 miles (63 km) east of Sheffield. It is England's furthest inland port at over 55 miles (89 km) from the North Sea.