The Duke of Devonshire was a traditional landed aristocrat, who owned, according to the 'New Doomsday Book' of 1873, the seventh largest
land, out of which he gained the second largest gross rental in the English landed aristocracy. He formed its central core. William Cavendish (1808-1884), who inherited the Dukedom in 1858, has been taken as a classic Mid-Victorian improving landlord. His entrepreneurship mainly covered the industrialisation and urbanisation
of Barrow-in-Furness. In 1846 he constructed the Furness Railway as a means of developing his own iron mines, in the 1860's created the Barrow
Haematite Steel Co. Ltd. and in the early 1870's a group of firms, which were related to the export of the steel rail. The firms respectively worked as elements which composed the productive forces for the use of landnature, and as a whole they created a regional structure of productive
forces for the use of natural resources. The Cavendishes completely grasped these firms, at first as 'a proprietary railway', next as a 'Furness Railway-Cavendish organism', and lastly as the 'Furness Railway's Industrial Empire'. It was made possible owing to the prosperity of England as World
Factory that the landowner transformed his own wealth into the capital on a large scale, led by the interest of his estate management. This was
the process of forming a 'Capital-Landownership Complex' proper to Modern England, in which on one hand the landowner partly came to base on the capital, and on the other hand English Capitalism mobilized the wealth ofthe landowner to the capital. The aim of this paper is to study the Duke of Devonshire's finance which supported the aggressive estate management. It brings light on the followings; 1. the 6th Duke's Finance in the 1850's, through the close study of the Chief Agent's General Statements of Income and Expenditure, 2. the state of the Duke Family's finance on the 7th Duke's succession to the Dukedom, through the careful examination of his the letters and diary, 3. his estate management and its finance between 1858 and 1884, through the analysis ofthe summary statement.