Peat reclamations of the Pre-Roman Iron Age and Roman Iron Age: Drainage ditch systems and settlement patterns in the province of Friesland, the Netherlands

Abstract

In the northern Netherlands, the fringes of the peat area adjacent to the salt marshes, with their well-known terp settlements, have been reclaimed and settled since the middle of the Pre-Roman Iron Age. Over time, settlement gradually expanded deeper into the peat area, until the reclaimed peat lands, like most of the salt marshes, were abandoned over the course of the Late Roman Iron Age. In the province of Friesland, two large areas with traces of these early peat reclamations have recently been researched using a combination of modern digital elevation maps and old aerial photographs dating back to the 1940s and 1950s. It proved possible to map 1100 km of former ditches and 508 possible archaeological sites, of which 453 locations had not previously been known. Further research could confirm that 135 of the 508 possible sites are sites of former settlements, of which 65 definitely back to the Pre-Roman Iron Age or the Roman Iron Age and 59 most likely or possibly date back to these periods. The remaining 354 locations still need to be researched, but based on various archaeological indicators, 176 of these could very well be sites dating back to the Pre-Roman Iron Age or Roman Iron Age. Of the mapped former ditches, 413.1 km proved to have been part of artificial drainage systems dating back to the Pre-Roman Iron Age or Roman Iron Age, and a large landscape feature could be identified as a former artificial embankment dating back to the same time period. Although much research is still needed, based on the current dataset it can be concluded that the early peat reclamations were intensively drained, densely settled and well organized. It seems very unlikely that these reclamations were only seasonally occupied, in contrast to what has been claimed by other researchers. Instead, it is much more likely the primary motive behind the early peat reclamations was the creation of an agricultural landscape that was suitable for mixed farming and inhabited year-round.