The main source for understanding the territorial structure of Gaelic Ireland in the later medieval period is the legacy of English versions of it which were constructed in the late sixteenth and early seventeenth centuries. These records are the consequence of a meeting of two societies with different, though not mutually unfamiliar,' perceptions of priorities in owning and working the land. The emerging modern state placed emphasis on measurement of acres, spaces and boundaries, expressed in surreys, ink-entories and maps of property and land values. The Gaelic world had a different sense of landscape and its economic and social significance. There was, however, a shape and spatial order to the Gaelic landscape, which in spite of cultural and tenurial differences was real and discoverable to the colonial authorities.