After the ploughed land with its crops and the grassland with its herds, the next thing is to build up a picture of the many different ways in which the two are combined in general farms, of how the rotations work out in practice, of how the different sorts of farming pay and of what keeps a man, and his wife, on the land. True, sheep, pigs and poultry are waiting for the next two chapters. They are vital to some farmers and to the country: wool was Britain’s first major export in medieval times and sheep have left the imprint of their golden hoof in the lovely old buildings still standing in parts of the country where sheep are now rarely seen, for the onward march of the plough has driven the herds of sheep mainly to the hill and upland farms. Pigs and poultry in the main are now indoors in ‘factory farms’ and although these enterprises may be part of a general farm, they are a specialised type of farming.