The Roman army had a voracious appetite. Its soldiers needed to be armed, housed and fed and in order to achieve this, both local and distant resources were required, their role and importance changing over time. The ranks of the legions at least included specialist craft-workers, and in all forts repairs would have been undertaken locally. However, much of the evidence rests on slender foundations and on analogy. In general, wherever possible, the army sought to obtain its supplies locally. This might have been achieved for many items of food and perhaps also leather, which was extensively used for a wide range of items (although the issue of goatskins, the key raw material for sheet leather such as tents but poorly attested in the bone record, remains debated; van Driel-Murray 2002, 109-111). Many key supply products, such as food, are near-invisible archaeologically; here pottery has great value as a proxy for wider supply routes, since it is generally argued that pots were not the prime import, but were traded for their contents or used as space-filler in larger cargoes.