Howard de Walden Estate

The Howard de Walden Estate is a property estate in Marylebone, Central London in the United Kingdom owned by the Howard de Walden family. As of 2014 the estate was estimated to be worth approximately £3.2 billion.

The Estate dates from 1715 when Edward Harley, 2nd Earl of Oxford and Earl Mortimer began the development of Cavendish Square in London, and the streets around it. This land had previously formed part of the Marylebone Estate of the Dukes of Newcastle. It had passed from Margaret Holles, née Cavendish, daughter of the 2nd Duke of Newcastle, to her daughter Henrietta Cavendish Harley. At the death of Henrietta's husband, the 2nd Earl of Oxford and Earl Mortimer, in 1741, this new Harley Estate passed to his only daughter, Margaret Cavendish Harley, who in 1734 had married William Bentinck, 2nd Duke of Portland. It was subsequently known as the Portland, and was handed down to successive Dukes of Portland. In 1879, the 5th Duke of Portland died without issue and his estates were divided between his sisters, according to the terms of the 4th Duke's will, and his cousin, who succeeded him as the sixth Duke. The Portland Estate eventually passed to the last surviving sister, Lucy Ellis, who was the widow of the 6th Lord Howard de Walden, and has remained in this family since then.

...
Wikipedia