A trouble-free and timely supply to navy and army was paramount and this inflexible imperative was not an advantage when obtaining provisions at a low price in the various agricultural markets. The Victualling Board and its agents could take few market risks, such as delaying purchase in anticipation of price decreases: and none at all on the core commodities of wheat, beef and pork. It had the advantage of being one of the largest purchasers in the market, with strong credit, and it had some powerful and well-connected agents working for it, which, as we shall see, carried the navy through some critical periods

The Victualling Board had the most politically sensitive task of all government offices, for it had to intervene in the markets to procure very large amounts of food. Domestically the government had to ensure that there was enough for a population which, including Ireland, grew from 14.5 million in 1791, to 15.9 million in 1801 and 18.1 million in 1811, a 20 per cent increase over the war years. At the same time the Board had to keep the government of the day free of political embarrassment and it was required to operate within considerable political limitations and demanding deadlines. It purchased, packed and preserved meat and foodstuffs, then distributed them against a background of other state demands on processed food resources, including the army at home, the concentrations of volunteers and militia formed to resist invasion in southern England, particularly in 1803 and 1804, and the Transport Board's task of feeding prisoners of war ‘in health’. Most prisoners were exchanged with the French and Spanish in the 1790s, but after the resumption of hostilities in 1803 almost no exchanges took place. Between 1803 and 1815, a total of 122,440 French, Danish and American prisoners arrived in the British Isles, of whom it is estimated that ten thousand died in hulks, depots and prisons. The highest prisoner population in any one year was 72,000.

The pattern for the purchase of produce had been established at least a century before, but there had been developments. During the eighteenth century common land had been enclosed in a great swathe from Northumberland to Dorset, and an estimated two million acres had come under cultivation.