We've completed the loop of the traffic roundabout, and are coming back up on Apsley House on Piccadilly. I discussed this place a little in image 190909_130548_0189.
In short, it was purchased by the Duke of Wellington, the victor of the battle of Waterloo, in 1817. It didn't look quite as it does now; in 1819 Wellington added a 3 story extension to the north-east, and in 1828 the "Waterloo Gallery" was added to the west side of the house.
At one time it was known as Number One London because if you were approaching London from the direction of Knightsbridge it was the first London house that you saw. Of course, London was a lot smaller at that time.
The maintenance costs on a place like this would have been astronomical, and of course by the mid-20th century the aristocracy no longer had sort of money that it had a century earlier. I suspect that is why the 7th Duke of Wellington bequeathed the house to the nation in 1947. It did come with a caveat, however; as long as there is a Duke of Wellington (we're on our 9th one at the moment, and he seems to be a very decent sort of guy), he retains the right to live there. The rest of the house is, however, available to be visited and should I return to London (screw you, Qantas) I would very much like to visit it. Aside from the architecture and the furnishings, it has an impressive collection of artwork.