Bullmastiffs are one of those breeds known as "gentle giants." Despite their size, these dogs are sweet-natured, calm and willing to please, making them excellent family pets and protectors. They are very intelligent and learn quickly. Bullmastiffs are not very active dogs and, despite growing to be up to 130 lbs. as adults, and can do well in an apartment as well as a larger space.
Bullmastiffs are hefty dogs, weighing up to 130 lbs., and most of that is muscle.
This breed was most likely developed around 1860 by Englishmen who sought a hunter with the strength of a Bulldog and the size of a Mastiff.