These were developed from a series of five locomotives (2631–2635), introduced in 1902 by Samuel W. Johnson, which had had a 3-cylinder compound arrangement on the Smith system. This had a layout of one high-pressure cylinder inside the frames, and two low-pressure cylinders outside, and utilised Smith's starting arrangement. On the first two locomotives, independent control of high-pressure and low-pressure valve gears was available. From 1905 onwards, Johnson's successor Richard Deeley built an enlarged and simplified version, eliminating all the Smith refinements whilst fitting his own starting arrangement, making the engines simpler to drive. These locomotives were originally numbered 1000–1029, but in the 1907 renumbering scheme the five Smith/Johnson locomotives became 1000–1004 and the Deeley compounds 1005–1034, ten more of these being added in 1908–1909. The original Johnson locomotives were all subsequently renewed as Deeley compounds, including the now-preserved 1000 which was rebuilt and outshopped with a superheater in 1914.
Numbered 1000–1044 by both the Midland and LMS companies, British Railways renumbered the Midland series of compounds 41000–41044 after nationalisation in 1948.
Number 1000 at Derby Works shortly after preservation
On 23 December 1904, locomotive No. 1040 was hauling an express passenger train that was derailed at Aylesbury, Buckinghamshire due to excessive speed on a curve. Locomotive No. 1042 was hauling an express passenger train that collided with the wreckage at low speed. Four people were killed.
On 19 January 1918, locomotive No. 1010 was hauling an express passenger train that was derailed when it ran into a landslip obstructing the line at Little Salkeld, Cumberland. Seven people were killed and 46 were injured.
On 10 July 1933, locomotive No. 1010 was hauling an express passenger train that was in a side-long collision with a freight train at Little Salkeld due to a signalman's error. One person was killed and about 30 were injured, one seriously.
On 12 April 1947, locomotive No. 1004 was hauling a passenger train which was derailed near Keighley, Yorkshire when a bridge collapsed under it.
On 21 April 1952, locomotive No. 41040 was one of two hauling a passenger train that was derailed at Blea Moor Loops, West Riding of Yorkshire when a defective brake hanger on the locomotive cause a set of points to move under the train.
No. 1000 was set aside for preservation after withdrawal and restored in 1959 close to its 1914 condition, painted in Midland maroon livery, running enthusiasts' specials until placed in the temporary Clapham Transport museum. Though steamed since preservation, it is currently a static exhibit at the Barrow Hill Engine Shed at Derbyshire, having been lent by the National Railway Museum in York.