3. Town lands and docklands
A quarter of the population of Wales lives within the boundaries of what were the lordships of the Marquesses of Bute and their personal estates.  These lands were centred on Cardiff Castle, which was the Welsh home of the Stuarts, of the Isle of Bute, from 1766 to 1947. Through their aristocratic status as Marquesses of Bute, and owners of land, in and around Cardiff, and vast properties above the eastern portion of the South Wales Coalfield, they wielded their considerable socio-political power to create a huge human ecosystem resourced by mining coal.  This family enterprise involved engineering an environment that resulted in the migration of people to the decayed market town of Cardiff and equally to the inhospitable sparsely populated uplands to the north, which became the hinterland of the largest docks in the world devoted almost entirely to the export of coal.
In 1766, when Lord Mountstuart of Bute married Charlotte Windsor, the daughter and co- heiress of Lord Windsor, the lands of the Bute family were augmented by a vast South Wales estate, which consisted of 11,211 acres of enclosed land, together with rights over a vast area of common land within the manors of east and mid Glamorgan.  Within the town of Cardiff itself  were 711 acres, with another 2150 acres surrounding the town in the parishes of Roath, Llanishen, Llandaf, Llandough, Leckwith, Cogan and Lavernock.  Another tract of 3,400 acres was centred on Llantrisant.  In the uplands of Glamorgan, extending from the Rhymney ato the Neath valleys, there were 4,100 acres, with an additional 850 acres around the Vale towns of Cowbridge and Llantwit Major.
More land was purchased by the family during the next one hundred and fifty years, and by the end of the 19th century the Bute estate had a virtual monopoly of land in the centre of Cardiff and the fringes of the town.  By this time the family estate amounted to about 22,000 acres.  It was the possession of these townlands, together with the extensive coastal grazing marshes around the estauary of the Taff and Ely rivers to the south of the town, that enabled the Bute family to generate wealth from a trio of resources; the rentals of urban development, the royalties from the mining of upland coal, and tolls from the passage of coal through the docklands that were created at the mouth of the River Taff. This unique integration of townlands and docklands placed the Bute estate among the richest personal properties of its size in the United Kingdom.
Its peak of prosperity coincide with the first signs of exhaustion of the South Wales mineral stocks. This factor, together with increasing professional complexities of administration, the low yield of the dock investment, the virtual extinction of the political influence of those with landed property, and the need to realise capital assets and to diversify investments, were all inducements to the fourth marquess to dispose of his Glamorgan possessions. Urban land in the industrial valleys was first put on the market in 1909, and this began a process which culminated in a large series of sales at Aberdare, Treorci and Treherbert in 1919 and 1920.   Between 1915 and 1919 the Bute collieries were disposed of, and in 1923 and 1924 a considerable proportion of the farms and other freehold property within the coalfied was sold. In 1922 the Bute docks were absorbed by the Great Western Railway Company.
In 1926 the surviving Bute property, largely mineral land under lease and urban land at Cardiff, was incorporated under the private family company of Mountjoy Ltd.  In 1938 Mountjoy sold its interests in leaseholds to the Western Ground Rents Company, and in the same year mineral reserves became the property of the state. By the second world war, therefore, all the major departments of Bute estate administration had been extinguished.
The gift of the castle to the corporation of Cardiff in 1947 was followed in 1950 by the deposit at the National Library of Wales of most of the papers relating to the Bute estate in Glamorgan, an act which brought to a close the period during which Bute administration dominated the cultural ecology of Cardiff and its valley communities.
From the 1950s the coal industry continued to decline and this was reflected in the prospserity Cardiff's docklands, which by the 1970s were virtually derelict. Through the workings of a government development corporation they were cleared of their old industrial legacy and, as 'Cardiff Bay', land with a new infrastructure was made available for business, housing and leisure. Cardiff Bay may now be studied as a model of civil engineering applied to promote private and public investment in post-industrialism, where 'living by water' is a major international theme of cultural ecology.