A third century crisis? The composition and metallurgy of Roman silver coinage; Septimius Severus to Valerian and Gallienus.

罗马银币的质量通常被认为是帝国经济健康的一个指标，银含量的下降被认为是财政不足的一个迹象。公元三世纪，贬值的银币开始主导罗马世界的货币体系，与此同时，历史学家将这一时期称为“三世纪危机”。从公元194年到260年，银币的银含量从不到50%下降到不到10%，以前的研究表明，这种质量的下降几乎是持续的。到公元260年左右，人们不得不采用新技术使硬币看起来像银一样，并掩盖它们主要由铜制成的事实。这种持续的衰退被认为预示着永久的财政危机，收入和资源无法与罗马在军队上的支出相匹配。人们普遍认为，公众对铸币的信心减弱，导致通货膨胀和货币体系崩溃。然而，这种货币危机解释所依据的证据存在严重缺陷。直到公元260年，罗马造币厂才能够通过一种被称为“耗尽镀银”的技术，故意增强硬币的银色表面，从而掩盖货币贬值的程度，而之前的分析并没有考虑到这一事实。因此，我们无法确定公元194年至260年间货币贬值的全面程度，也无法确定货币贬值的频率。我们不知道在这一时期是否有长期的稳定甚至改善。虽然毫无疑问，公元260年的银含量比公元194年要低得多，但银含量下降的方式以及下降的原因仍然不清楚。申请人在早期的工作已经推翻了那些时期持续衰退和永久财政危机的图景。“三世纪危机”的基石之一——铸币的崩溃——是否能持续下去，还有待观察。该项目的目的是分析公元194年至260年期间的2250枚罗马银币，不仅要确定硬币的纯度，还要使用微量元素和铅同位素分析，以告知我们原材料的来源和生产技术。银币中银含量急剧下降的一种解释是，罗马帝国用光了新鲜的白银储备。如果是这样的话，回收的证据应该是显而易见的。此外，体重标准也将受到严格审查。这对于比较不同面值的银币很重要，但它们也是货币标准概念的重要组成部分。最后，一项关于囤积的研究将寻找公众意识到硬币变化的证据。PI和Co-I组成了一个强大的跨学科团队，由考古冶金学家和古代历史学家/考古学家密切合作，并在这一主题上取得了20多年来的成功协同合作记录。总结一下：目前我们对公元194年至260年间罗马银币的状况几乎一无所知，这一时期导致了假定的货币崩溃。通过跨学科的研究，该项目将把计量、纯度标准、囤积证据、金属供应和生产技术结合起来，在罗马帝国货币历史的关键时刻提供罗马银币的全面画面。

The quality of Roman silver coinage is often taken an an index of the economic health of the empire, with a fall in silver content being taken as an indication of fiscal inadequacy. During the third century AD debased silver coinage came to dominate the currency system of the Roman world, coinciding with a period that historians have dubbed the 'third century crisis'. Between AD 194 and 260 the silver content of the coinage declined from just under 50% to less than 10%, and previous studies have proposed that this decline in quality was almost continuous. By about AD 260 new technologies had to be employed to make the coins look silvery and to disguise the fact that they were made mainly of copper. The continuous decline is thought to signify perpetual fiscal crisis, where revenues and resources could not match Rome's expenditure on its armies. It is generally thought that public confidence in the coinage waned, leading to inflation and the collapse of the monetary system. However, the evidence on which this account of monetary crisis is based is seriously flawed. Until AD 260 Roman mints were able to disguise the extent of debasement by deliberately enhancing the silvery surfaces of the coins using a technique known as depletion silvering, and previous analyses did not take this fact into account. Consequently we do not know anything for certain about the full extent of debasement between AD 194 and 260, or about the frequency of debasement. We do not know whether there were long periods of stability or even improvements during this period. While there can be no doubt that the silver content in AD 260 was much lower than in AD 194, the way in which the decline occurred - and thus the reasons for the decline - remain obscure. Previous work by the applicants on earlier periods have overturned the picture of continuous decline and perpetual fiscal crisis for those periods. It remains to be seen whether one of the cornerstones of the 'third century crisis', the collapse of the coinage, is a sustainable narrative.The aim of the project is to analyse 2,250 Roman silver coins for the period AD 194 to 260, to determine not only the fineness of the coins but also to use minor and trace elements, and lead isotope analyses, to inform us about sources of raw materials and production technology. One explanation for the dramatic fall in the silver content of the coinage is that the Roman empire ran out of stocks of fresh silver. If this is so, evidence of recycling should be readily apparent. In addition, weight standards will also be scrutinised. These are important for drawing comparisons between different denominations of silver coinage, but they are also an important component of the concept of monetary standards. Finally, a study of hoards will look for evidence that the public was aware of changes made to the coinage.The PI and Co-I form a strong interdisciplinary team of archaeometallurgist and ancient historian/archaeologist working closely together and with a successful track-record of synergistic collaboration on this topic going back over two decades.To summarise: currently we know almost nothing about the condition of Roman silver coinage between AD 194 and 260, the period leading to the presumed collapse of the currency. Through interdisciplinary study, this project will bring together metrology, fineness standards, hoard evidence, metal supply and production technology to provide a comprehensive picture of Roman silver coinage at a crucial point in the monetary history of the Roman empire.