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Warning: This is not intended to be an exhaustive history of the companies listed, but an indication of the changes of ownership and the links between companies and directors in those companies. Only collieries, pits etc. in the North of England are shown - the companies may own other properties etc. outside this area and there may have been other changes of ownership etc. for which we currently do not have details.
Entries added or updated since 01 Jun 2008 are highlighted thus: 
| Company | Company Details | |
|---|---|---|
| Dean Moor Colliery Co. Ltd. | 1923, 1933, 1937, 1940, 1947 | |
| Dearham Colliery Co. Ltd. | ||
| Derwent & Consett Iron Co. Ltd. | ||
| Derwent Fells Mineral Estate Ltd. | ||
| Derwent Iron Co. | ||
| Dicken House Colliery Co. Ltd. | ||
| Dorman, Long & Co. Ltd. | 1923, 1933, 1940, 1947 | |
| Dunn's House Colliery Co. | 1923, 1933 | |
| Dunston Garesfield Collieries Ltd. | 1923, 1933, 1940, 1947 | |
| Dunston, Norwood, & Swalwell Garesfield Coal Co. | ||
| Durham County Coal Co. | 1836 | |
| Durham, Earl of | 1888 |
