Which was the mightiest in its old command”
Byron, Childe Harold’s Pilgrimage, Canto IV, 1818.
The next line has … “and is the loveliest”.
England’s landscape declined with its power. The trajectories were different, but (if you have anything like a classical view of landscape) they were in decline together from the moment English power started to decline.
The great twentieth-century popular historian of the English landscape was WG Hoskins, who published The Making of the English Landscape in 1955. That link is to a Wikipedia article which contains a summary of the book. The story was set in a wider historical context for the same generation, which had a stronger memory of old landscapes than we do, by GM Trevelyan (post here). For Trevelyan, the English landscape was still at its loveliest in 1818.
But would the Romans have recognised the Italian landscapes of 1818? I asked my friend Giovanni Caselli this question. I will post his reply tomorrow.