Islamic gardens, with their waterways and beds of plants and trees, are generally regarded as an earthly reflection of paradise. D. Fairchild Ruggles offers a different interpretation, contending that the palace garden was primarily an environmental, economic and political construct. She discusses three aspects of medieval Islamic Spain: the landscape and agricultural transformation documented in Arabic scientific literature, the formation of the garden and its symbolism from the eighth through to the 15th centuries, and the role of the gaze and the frame in the spatial structures through with sovereignty was constituted. Although the repertory of architectural and garden forms was largely unchanged from the 10th to the 15th centuries, Ruggles explains that their meaning changed dramatically. The royal palace gardens of Cordoba expressed a political ideology that placed the king above and at the centre of the garden, and metaphorically, of his kingdom. This conception of the world began to falter in later centuries, but patrons clung to the forms and motifs of the golden age. Instead of creating new forms, artists at the Alhambra in Granada reworked and refined familiar vocabulary and materials. The vistas fixed by windows and pavilions referred not to the actual relationship of the king to his domain, but rather to the memory of a once-expanding territory.