The Gamekeeper's Dog aka The Bullmastiff

MASTIFF + BULLDOG + BULLMASTIFF

In the mid-19th century, English gamekeepers needed a guard dog to assist the gamekeeper in keeping the game from being poached (stolen for food by starving peasants).

This dog had to be alert enough to see poacher, have the instinct to protect the property, be quiet enough to not alert the poachers, be fast enough to catch the poachers and be strong enough to hold them until the game-keeper got there.

Mastiffs, while imposing in size, were too slow and not aggressive enough. The Olde English Bulldogs of that time were too ferocious and tore the poachers apart (not good). So the gamekeepers crossed the Mastiff and Bulldog until they achieved the perfect mix of 60% Mastiff and 40% Bulldog…the Bullmastiff.

The brindle coloration was favored originally, as the darker striped pattern blended in better at night in the forest. But as the grand English country estates became fewer and fewer and the Bullmastiff found other work, the fawn color became more popular.

The GRAND ESTATES of GREAT BRITAIN IN 1800s from Wikipedia

The great houses are the largest of the country houses; in truth palaces, built by the country's most powerful – these were designed to display their owners' power or ambitions to power. Really large un-fortified or barely fortified houses began to take over from the traditional castles of the crown and magnates during the Tudor period, with vast houses that were more like castles.  

Such building reached its zenith from the late 17th century until the mid-18th century; these houses were often completely built or rebuilt in their entirety by one eminent architect in the most fashionable architectural style of the day and often have a suite of Baroque state apartments reserved for the most eminent guests, the entertainment of whom was of paramount importance in establishing and maintaining the power of the owner.

During the 18th and 19th centuries, for the highest echelons of English society, the country house served as a place for relaxing, hunting and running the country with one's equals at the end of the week, with some houses having their own theatre where performances were staged.

The country house, however, was not just an oasis of pleasure for a fortunate few; it was the centre of its own world, providing employment to hundreds of people in the vicinity of its estate. In previous eras, when state benefits were unheard of, those working on an estate were among the most fortunate, receiving secured employment and rent-free accommodation. At the summit of this category of people was the indoor staff of the country house. Unlike many of their contemporaries prior to the 20th century, they slept in proper beds, wore well-made adequate clothes and received three proper meals a day, plus a small wage. In an era when many still died from malnutrition or lack of medicine, the long working hours were a small price to pay.

For many, this way of life, which began a steady decline in 1914, continued well into the 20th century, and for a very few continues to this day.