According to Thorold Rogers, the cattle of the Middle Ages were small rough animals like the mountain breeds of to-day, and at the end of the sixteenth century we have seen they had large horns, were low and heavy, and for the most part black.[736] The great variety of cattle in Great Britain may be due to their being the descendants of several species, or to difference of climate and soil, or to spontaneous variation, but the chief cause is the diligent selection of breeders. Marshall is quite positive[737] that the Hereford, Devon, Sussex, and the black mountain breeds of Scotland and Wales are all descended from the original native breed of this island, that the Shorthorns came from the Continent, and the Longhorns probably from Ireland. Bradley's division of cattle into black, white, and red tells us little.[738] There was very little attempt at improvement until the middle of the eighteenth century, for peace was necessary for long continued effort, and 1746, the date of Culloden, the last battle fought on British soil, may be taken practically as the commencement of the era of progress. The Shorthorn is the most famous and widely-spread breed of this country, if not in the world; it exceeds in number any other breed in the United Kingdom, and most cross-breds have Shorthorn blood in them. It adapts itself to any climate, and is equally noted for beef-making and milk-yielding. The origin of the Shorthorns is uncertain; they originated from the Teeswater and Holderness varieties, but where these came from is a matter of dispute. Young, in his _Northern Tour_,[739] says, 'In Yorkshire the common breed was the short-horned kind of cattle called Holderness, but really the Dutch sort'; and many have said the Holderness and the Teeswater breeds both came from Holland, and were practically the same, while others assert the original home of the Teeswaters was the West Highlands.[740] John Lawrence speaks of the Dutch breed with short horns in 1726;[741] but, unless they were smuggled over, it certainly seems strange that any Dutch cattle should have been imported in the eighteenth century, for the importation of cattle was strictly forbidden during the whole century. It was George Culley's opinion that they came from Holland, because few were found except along the eastern coast; he also knew farmers who went over to Holland to buy bulls.[742]