of them would be lost. There could be hundreds of reasons why they were lost, from sheer bad luck to barbarian attacks, but the reason must usually remain guesswork.
The first silver periodThe first 44 hoards, chronologically speaking, are listed in Table 1 and the first half of Table 2, and are hoards of coins of the first and second centuries, when the economy was stable and good quality gold and silver coins were available (even though the silver was gradually being de-based).
The first thing that strikes us is the wide range of emperors and dates represented by the coins in each hoard, a range of up to 200 years in some cases. Many date back to the Roman Republic. This doesn't mean that each hoard was being amassed over a long period of time. What it does mean is that all of the coins represented in each hoard were still circulating in Britain at the closing date of that hoard. Closing dates of hoards are spread out evenly over the entire period, indicating perhaps that they were not buried as a response to a particular danger, but as a matter of every-day security.
If the idea of denarii circulating 200 years after they were made is difficult to swallow, consider this: Could one family have accumulated them year in year out for 200 years and if so, why, since the oldest and the newest coins would have had equal value. Perhaps the hoard was started 10, 20, 30 years before it was eventually lost. In that case where would the older coins come from to start that hoard? Only from circulation.
Claudius conquered Britain in 43 A.D. and Roman coinage was introduced. No Roman mints were set up in Britain, and money to pay the army and administration was sent from mints in Rome or elsewhere. Those lucky enough to be in receipt of a salary or payment in these coins were expected to pay their taxes in the form of silver denarii. To the rest of the population, a denarius was a high value coin, so apart from the nouveau riche, they mainly remained outside this economic cycle and stuck to barter. Consequently, Britain remained only partially monetised during the first century and the first half of the second. The new province was also expected to be self sufficient, so fresh cash was required only to top up shortfalls in the tax receipts. Shipping coins back to Rome simply for melting and re-issue would not have been very cost effective. Very few coins seem to have gone in and out of Britain in trading activity. The coins that arrived in the province therefore tended to stay there and the result was a 'closed' circulation.
According to calculations by R. A. Abdy, over the period represented by any given hoard, the distribution of coins tends to peak somewhere in the middle of the period, tailing off at the beginning and the end of the period. This is because older coins have had longer to be removed from circulation, while newer coins have not yet reached full circulation. This can more or less be seen in Table 1 and the first half of Table 2, bearing in mind that the listings are by emperor, each of which might have had a long or short reign with the resulting differences in the number of coins issued. One consequence of this is that for smaller hoards the ends of the 'graph' can go below zero, so that the oldest and newest coins that would have been in circulation may not be present in the hoard, so the deposition date may be much later than the date of the most recent coin in the hoard. Conversely, for large hoards, the deposition date is most likely to be straight after the date of the last coin(s).
The coins in the first eight hoards in Table 1 mostly come from before Claudius's invasion. It shouldn't be assumed that the pre-Claudian coins necessarily arrived with the invaders, as Roman coins were present in Britain before then, as a result of trading, gifts to tribal leaders and the wages earned by British mercenaries. In fact, two of the hoards, Llanhamlach, Wales (Table 1, D182), and Selby, North Yorkshire (Table 1, A117), were in areas still outside direct Roman control. The Woodbridge, Suffolk, find (Table 1, C238) also 