SETTLEMENT up TO 1850 From mediaeval times until the start of the nineteenth century there was a steady expansion of the overall settlement pattern. After 1850, the documentary evidence shows that depopulation had affected the cultural landscape, and many settlements were abandoned. Robert Owen in 19032 pointed out that the houses of the gentry in the river basin had already been deserted. Initially they served as the residences of branches of the Powis family, and of the local gentry. Frequently they functioned as seasonal homes, the family returning to the lower lands and the towns for the winter season. Mount Hall near to Llanfair Caereinion was built as a residence for a retired Liver- pool town clerk. These settlements were all distinguished from the native settle- ments by the substantial architecture and the number of outhouses, and by their setting in a parkland. The sites were invariably in the lower reaches of the river basin, on alluvial stretches and fans, below the 800 ft. contour line. Accessibility was an important factor in the choice of site, and a southerly aspect was sought after, especially since the parkland would include many shrubs and trees of a Medi- terranean origin. By 1800, however, it appears that decay had set in both for the fabric of the houses and their geographical distribution. Of the native farms, those which resulted from the mediaeval laws are the pre- dominating element and the more traditional in the "tyddyn landscape."3 The "hafotai" of the moorlands, found chiefly above the 800 ft. contour line and asso- ciated with transhumance, are also within this group. The map shows the possible area of the "tir priod" of the "tref", and on this land the "ty hir" (long-house)4 is the predominating type of native architecture. In the moorland (the "cytir" of tribal Wales) many "hafotai" also were of this architecture, but more commonly the summerhouse was simpler in design, consisting frequently of a single room. Of the second element in the settlement pattern, the chief characteristics are that the houses are mostly on the former "cytir" (commonland) and are architec- turally crofts. They resulted from "tai-un-nos" and "cabanau-un-nos" practices. Their initial appearance in the settlement pattern is possibly early in Mediaeval times, but unlike the earlier group, they continued to be set up at least until the time of the Parliamentary Enclosure Acts of 1812. (2) Owen, Robert, Uyfyr Goch Caereinion The Official Handbook to Caereinion, Welsh- pool, 1903. (3) Howe, Melvyn, Wales from the Air, Cardiff, 1957. (4) Peate, Iorwerth, The Welsh House, Liverpool, 1943. (5) Sayce, R. U., "Popular Enclosure and the One-Night House," Mont. Coll., Vol. 47, 1942.