The concept of interest-bearing debt has been traced as far back as ancient Sumeria – that is, to well before the existence of fiat currency like coinage – and it seems to be well established that it caused significant economic instability over time. Certainly a number of Bronze Age societies dealt with the problems created by debt bondage by occasionally declaring what economists term "clean slates". This means there is a long history of the proclamation of edicts devoted to cancelling rural debts, liberating bondservants and restoring land-rights to cultivators who had forfeited them.

The law code of Hammurabi, the king of Babylonia (c.1750 BC), makes several mentions of debt. It establishes that a man is responsible for the debts contracted by his wife, including those contracted before their marriage, while a wife cannot not be arrested for her husband's pre-marital debts; both, together, were responsible for the debts contracted during their marriage.

Hammurabi also offers several options to the indigent debtor, which together show that it was not easy or straightforward to wriggle out of such obligations in his kingdom. Clause 51 of the code covers what happens in the event that a debtor "have no money to repay" - "he shall pay in corn or sesame in place of the money." And Clause 117 gives a man the option of selling his wife, son or daughter (or all three) into servitude to discharge his debt, by binding them to over "for three years" to the creditor, although the creditor has to promise they will receive their freedom in year four.

It is Clause 48 that specifies the circumstances in which some debts may be, if not forgiven, then at least postponed – but these involve essentially events that modern insurance companies (and one presumes contemporary Babylonians) would consider "Acts of God":

If a man owe a debt and Adad inundate his field and carry away the produce, or, through lack of water, grain have not grown in the field, in that year he shall not make any return of grain to the creditor, he shall alter his contract-tablet and he shall not pay interest that year.

An alternate translation of the same clause, which perhaps makes the same provision clearer to us in more modern terms would be:

If any one owe a debt for a loan, and a storm prostrates the grain, or the harvest fail, or the grain does not grow for lack of water; in that year he need not give his creditor any grain, he washes his debt-tablet in water and pays no rent for the year.

Similarly, the Rosetta stone, or "Memphis Decree," was indeed raised to record a proclamation, made by Ptolemy V in 196 BC, announcing an amnesty for debtors and prisoners. The relevant part of the text (in sections 12-17) reads:

He hath given unto the soldiers who are in his august service . . . . . . according to their rank [and of the taxes] some of them he hath cut off, and some of them [he hath lightened], thus causing the soldiers and those who live in the country to be prosperous under his reign [and as regards the sums which were due to the royal house] from the people of Egypt, and likewise those [which were due] from every one who was in his august service, His Majesty remitted them altogether, howsoever great they were; and he hath forgiven the prisoners who were in prison, and ordered that every one among them should be released from [the punishment] which he had to undergo. And His Majesty made an order saying:—In respect of the things [which are to be given to] the gods, and the money and the grain which are to be given to the temples each year, and all the things [which are to be given to] the gods from the vineyards and from the corn-lands of the nome, all the things which were then due under the Majesty of his holy father shall he allowed to remain [in their amounts] to them as they were then; and he hath ordered:—Behold, the treasury (?) shall not he made more full of contributions by the hands of the priests than it was up to the first year of the reign of His Majesty, his holy father; and His Majesty hath remitted To the priests who minister in the temples in courses the journey which they had been accustomed to make by river in boats to the city of Alexandria at the beginning of each years and His Majesty commanded:—Behold, those who are boatmen [by trade] shall not be seized [and made to serve in the Navy]; and in respect of the cloths of byssus [which are] made in the temples for the royal house, he hath commanded that two-thirds of them shall be returned [to the priests]; similarly, His Majesty hath [re]-established all the things, the performance of which had been set aside, and hath restored them to their former condition, and he hath taken the greatest care to cause everything which ought to be done in the service of the gods to be done in the same way in which it was done in former [days]...

As the final few words of this extract suggest, Ptolemy's decree was not unprecedented. We know from Greek sources that Bakenranef (r.720-715 BC) issued a decree that abolished debt bondage and annulled all outstanding liabilities in the run-up to a war, as he thought it

would be absurd for a soldier, perhaps at the moment when he was setting forth to fight for his fatherland, to be hauled off to prison by his creditor for an unpaid loan.

(The same decree has been used to suggest that the concept of a debtors' prison must have existed in the Egypt of the Third Intermediate Period. Such prisons probably also existed in ancient Babylon; the Code of Hammurabi has several clauses (114,115) that cover what happens if a creditor seizes a debtor for non-payment.)

So what can we conclude about the purpose for which the Rosetta Stone was originally carved? We know that the Memphis Decree was issued during a period of turmoil in Egypt, at a time when the Seleucids were attempting to seize and divide up Egyptian territory and Ptolemy was facing internal rebellion as well. Thus circumstances, precedent and the stone's mention of more money for soldiers and the possibility of impressment into the Egyptian navy all suggest it probably, like Bakenranef's decree, has something to do with preparations for war.

All this brings us to the problem underpinning your enquiry. Your source argues that modern state and institutional creditors should consider cancelling the debts owed to them, and hence is keen to make the point that "generalised debt cancellation has occurred throughout history." It further argues that "four general cancellations took place during Hammurabi’s reign, in 1792, 1780, 1771, and 1762 BC."

Here your source is referring to so called misharum edicts, not to the law code of Hammurabi itself. These were rare beasts, issued by Babylonian rulers either when they came to the throne, or at times of extreme economic difficulty. Those issued by Hammurabi certainly have been interpreted as wide-ranging financial restructurings that were part of broad agrarian reform programmes. However, it's important to make three key points about these edicts.

First, they were not simply munificent gestures made by great and generous kings – rather, they were undoubtedly political in nature. The main reason for issuing them was either to secure support for a new regime (in the case of edicts issued on accession to the throne) or retain and re-secure support in times of political or economic difficulty. The first of Hammurabi's edicts was issued on his accession. But the purpose of the latter three seems to have been to ensure that the limited supplies of fertile Babylonian land remained available to the state for issuing as a reward to Babylonian soldiers, rather than passing into the hands of rent-seeking private speculators.

Second point. Misharum edicts were couched in explicitly religious terms, which may suggest an attempt to set controversial and unwelcome political decisions in the sort of language that made them hard to dissent against. Hudson puts it this way:

The designated occasion for clearing Babylonia's financial slate was the New Year festival, celebrated in the spring. Babylonian rulers oversaw the ritual of "breaking the tablets," that is, the debt records, restoring economic balance along with the rest of nature."

Thirdly and finally, the misharum edicts weren't explicitly linked to Hammurabi's code of laws. As i touched on above, they were grand political gestures that stood outside it, and indeed contradicted some of its specific terms.

Much of what you'll read online about these programmes and the idea that generalised debt forgiveness has a lengthy history has been written to support the delivery of a specific and modern political message – Hudson's first work, for example, was Super-Imperialism (1972), a vigorous critique of contemporary US policy, and the 1993 book of his I cite was published by Pluto Press, which was certainly the most radical significant publishing house in the UK at that time.

On this basis, I'd caution against any interpretation of either Hammurabi's code or the Rosetta stone as an example of "generalised" debt forgiveness. Whatever the motives Babylonian kings may have had for issuing misharum edicts, and Egyptian Pharaohs for making their decrees, both these records indicate that, for the most part, debt was most likely forgiven chiefly for valued political and military supporters, and then only in very specific, politically and economically sensitive, circumstances.