[Flavius Magnus Aurelius Cassiodorus Senator, “Variae”, lib. XII, ep. 22, 537-540 AD.]
The true way to prevent the requirements of the public revenue from becoming oppressive, is to order each Province to supply those products in which it is naturally most fertile.
Now I have learned by conversation with travellers that the Province of Istria is this year especially blessed in three of its crops—wine, oil, and corn. Therefore let her give of these products the equivalent of ... solidi, which are due from you in payment of tribute for this first Indiction: while the remainder we leave to that loyal Province for her own regular expenses. But since we require a larger quantity of the above-mentioned products, we send ... solidi from our state chest for the purchase of them, that these necessaries may be collected for us with as little delay as possible. Often when you are desirous to sell you cannot find a purchaser, and suffer loss accordingly. How much better is it to obey the requirements of your Lords than to supply foreigners; and to pay your debts in the fruits of the soil, rather than to wait on the caprices of a buyer!
We will ourselves out of our love of justice state a fact of which you might otherwise remind us, that we can afford to be liberal in price because we are not burdened by the payment of freights [on account of your nearness to the seat of government]. For what Campania is to Rome, Istria is to Ravenna—a fruitful Province abounding in corn, wine, and oil; so to speak, the cupboard of the capital. I might carry the comparison further, and say that Istria can show her own Baiae in the lagunes with which her shores are indented, her own Averni in the pools abounding in oysters and fish. The palaces, strung like pearls along the shores of Istria, show how highly our ancestors appreciated its delights. The beautiful chain of islands with which it is begirt, shelter the sailor from danger and enrich the cultivator. The residence of the Court in this district delights the nobles and enriches the lower orders; and it may be said that all its products find their way to the Royal city. Now let the loyal Province, which has often tendered her services when they were less required, send forward her stores freely.
To guard against any misunderstanding of our orders, we send Laurentius, a man of great experience, whose instructions are contained in the annexed letter.
We will publish a tariff of moderate prices when we next address you, and when we have ascertained what is the yield of the present crops; for we should be deciding quite at random before we have received that information.