The new line would connect it, and the Manchester and Leeds Railway as part of a trunk route from the South and London to Yorkshire and the North East of England.

It would be 72 miles (116 km) long, meeting the York and North Midland, at Normanton, and also the projected Manchester and Leeds Railway.

[2] Stephenson decided the line would follow the river valleys from Derby to Leeds, with minimal gradients and large radii curves.

By that time, Stephenson, who was wishing to concentrate in exploiting the coal around Ashby-de-la-Zouch, delegated the responsibility for almost the entire work of its design and construction to his engineer Frederick Swanwick.

Although the general radius of curves was one mile (1.6 km), gradients were as steep as 1 in 264 and practically the whole length was embanked or in cuttings, when not proceeding through a tunnel.

The original intermediate stations were Belper, Amber Gate, Wingfield, Chesterfield, Eckington, Beighton, Masbrough, Swinton, Darfield, Barnsley, Oakenshaw, Normanton and Woodlesford.

Although praising their design, Whishaw was somewhat critical: "we cannot but deplore the growing evil of expending large sums of money on railway appendages.

Instead of cottage buildings, which, for the traffic of most of the intermediate stopping places on this line, would have been amply sufficient, we find the railway literally ornamented with so many beautiful villas, any one of which would grace the sloping lawn of some domain by nature highly favoured.

However, he added "The doorways ... are in so exposed a situation as naturally to shock the female portion of travellers, who, while the trains are stopping, cannot fail to observe the constant bustle about these buildings.

On 30 November 1842 at a meeting in Derby, John Walbanke Childers MP, Mr. Pickersgill, Hatton Stansfield, T. B. Pease, F. Carbutt, and Mr. Hall retired from their positions as directors, and W. L. Newton (chairman), A. Titley (deputy-chairman), Mr. Laycock, Mr. Lee, Mr Cox and J. Holdsworth remained.

[9] Boys, instead of men, would work points at junctions, services were reduced and fares raised and a number of carriages were sold.

The remainder (43 enginemen, stokers and turners) protested over the lower wages, and were sacked as well, on Christmas Eve 1842[10] and without pay in lieu of notice.

He then negotiated a secret amalgamation with the Birmingham and Derby which would remove all the Midland Counties' trade and, in August, returned to the latter with an ultimatum.

Finally, on 22 September 1843, at a meeting in Derby under the chairman of the Directors, William Leaper Newton, the triple merger was agreed.

In addition, the section from Derby to Ambergate, where the Manchester, Buxton, Matlock and Midlands Junction Railway diverged, has local services as part of the Derwent Valley Line, whilst the section north from Clay Cross is served by other East Midlands Railway services on the Nottingham–Sheffield corridor.

The section north from Beighton Junction to Rotherham Masborough (the "Old Road") has been freight-only since July 1954, although it is very occasionally used as a diversionary route and by excursions not calling at Sheffield.

This section has been subject to several changes as a result of integration with the parallel former Great Central Railway line between Sheffield and Mexborough.

Stopping passenger trains between Sheffield and Leeds via Cudworth were withdrawn in January 1968, with all of the remaining stations between Rotherham Masborough and Normanton closing at that time.

By May 1972 however the Swinton and Knottingley line was experiencing subsidence of its own, resulting in the reopening of the North Midland section to passengers.

Today the section from Swinton (Wath Road Junction) to Cudworth North Junction has been lifted; the entire length of well over a mile between Wath Road Junction and the site of Wath North station itself has been eradicated by a large new area of light industry and commerce called Brookfield Park, one of the largest developments of its kind in the country and part of the Dearne Valley Enterprise Zone (much of this area being the former site of Manvers Main Colliery and several others), while about three quarters of a mile of the route north of Darfield is now a road (the A6195).