The Berkshire became the favourite pig of the nineteenth century, widely used to improve other British pigs and to produce crossbreds for slaughter, but its popularity declined during the twentieth century until it became a rare breed.
Today the Berkshire is an attractive-looking prick-eared breed - said to have a good sense of humour - and has improved considerably to meet more modern tastes in recent years. Although it is black-haired (with touches of white on the legs, face and tail switch), its carcass 'dresses out' white, and the flesh is fine, with a high proportion of lean to fat; and it matures early. The sows make excellent easy-going mothers with plenty of milk for their litters, which average nine piglets.

The English midlands in the eighteenth century was the heartland for slouch-eared, splodgy-coloured pigs. There was, for example, a large hefty spotted curly-coated Warwickshire pig, a red-and-black or brindle Shropshire pig (as well as a better-quality Shropshire white), wire- coated black-and-white spotted pigs brought across the border from Wales, blue-and-white Cheshire pigs, red-and-white pigs in Herefordshire, and a mixture of white, coloured and spotted Staffordshire pigs that were either large and slouch-eared or smaller and prick-eared.

By the early eighteenth century there was plenty of variation in British pigs. Some were communal scavengers; some were cottage pigs; some lived well on the by-products of dairy and arable farming. Gradually regional types developed, differing in the carriage of their ears, the length of their bodies and legs, and their skin and coat colours. There was a broad tendency for white pigs to be favoured in the north (the famous Yorkshire pigs, for example), black or black-and-white pigs in the south, and spotted and blotched multi-coloured pigs of red, black and sand in between.

Domesticated pigs in medieval Britain contrasted with the Wild Boar in that they tended to have lop ears rather than pricked and their tails tended to be curly rather than straight.
For many centuries the typical Old English hog had big slouching ears hanging over its eyes (said to make the animal more docile as it could not see where it was going), a narrow razor back, low shoulders, flat slab sides, a long rootling snout, and long strong legs so that it could range widely in its foraging and walk long distances to market. It was a large-framed, hairy animal, slow to grow, and usually a dirty yellow- brown in colour, with or without spots or belts of another colour. This was the common 'Celtic' domestic pig of northern Europe.

The ancestor of the British domestic pig is the native Eurasian Wild Boar (Sus scrofa), which used to range all over Europe and Asia, in climates varying from typically British to Siberian and tropical. The domestic pig, under the skin, is not so different from the Wild Boar.
The Wild Boar's natural environment is woodland, scrubland or steppe, with the luxury of a muddy place to wallow on occasion. The animals live in a matriarchal society based on one or more females and their daughters; the males tend to live separately. Sows might have up to fifteen striped piglets in a litter, but they have only a dozen teats and in most cases each piglet demands its own teat. Wild Boar, like other wild pig species, are vocal and communicate constantly within the family group with grunts and squeaks. They feed mainly on plants (foliage, roots, fruit, bulbs) and fungi but will also eat earthworms. Their ability to rootle into plant debris and moist soil is legendary.

Most domestic pigs have curly tails, though wild pigs and many Asian domestic pigs have straight tails. The most obvious characteristics that differentiate the various pig breeds are the carriage of the ears, the shape of the face, the colour of the skin and coat, and the general conformation - body shape and size.
Ears range from 'prick' (upright) to 'lop' (falling over the face), with a range of semi-prick and semi-lop in between. Snouts range from long and tapered, typically seen in the Wild Boar, to dished, snubbed and squashed in breeds influenced long ago by Asian imports.

You cannot make bacon, as you can milk, merely out of the garden. There must be something more. A couple of flitches of bacon are worth fifty thousand methodist sermons and religious tracts. The sight of them upon the rack tends more to keep a man from poaching and stealing than whole volumes of penal statutes, though assisted by the terrors of the hulks and the gibbet. They are great softeners of the temper and promoters of domestic harmony. They are a great blessing ...'

The sudden disappearance of pigs from the British landscape within living memory was remarkable. They have become no longer a familiar sight — to the extent that many people today are startled at the large size of a fully grown pig.
As recently as the 1950s, outdoor herds had been the norm on every pig farm. In addition, most smallholders reared a few outdoor pigs, and before the Second World War many a cottage dweller still kept the traditional family pig at the end of the garden, fattening it on household scraps, orchard windfalls and vegetable-patch waste, and regarding it almost as a member of the household — apart from its destiny as home-killed, home-cured meat for the table.
In the post-war decades pig farming changed radically and many pigs became hidden from public view, raised on a large scale within purpose-made buildings where highly bred and efficient commercial animals were intensively reared to supply consumers with affordable bacon, pork and sausages.