Most people choose a dog because they like its appearance. Far more important than appearance in day-to-day living with an animal is it's temperament and behavioral tendencies.
The Bullmastiff came into existence as a companion and coworker with the British gamekeeper. As previously mentioned, at the time of the development of the breed, poaching game was a capital offense. The gamekeeper needed a strong, agile, intelligent, and obedient dog to assist him in his work and for his own protection. The Gamekeeper's Night Dog, the forerunner of the Bullmastiff as we know it today was just right for the job.
Not only does the Bullmastiff have all these characteristics, but he is also possessive and strong willed. He is not the dog for a person who will not combine affection with consistency and discipline. Remember in purchasing a Bullmastiff that this breed was developed as a GUARD dog. While a proper Bullmastiff is loving and friendly, he still has a strong instinct to try to control a situation. A dog is a pack animal. The family he lives with, and any other animals he lives with are his pack. In every pack there must be a leader, and there is a hierarchy, or pecking order. The dog must know his place to be comfortable in his surroundings and mentally secure in his status in life. The dog must ALWAYS defer to all the members of the household and accept any friends welcomed by the family. The exception to this is that no dog should be subjected to teasing and ill treatment. Children and guests should be clearly educated to the fact that the dog is a living, feeling creature, and not some sort of toy.
The Bullmastiff's combination of power, intelligence, and strong will, and devotion make him wonderful companion for someone looking for a dog with character. Life with a Bullmastiff is seldom dull. Control must be established by the owner from the SECOND one takes possession of the dog.
Bullmastiffs make excellent companions and guards because in their minds THEY OWN YOU. They will try anything to get their own way. Males will generally try to force the issue or pout; females usually try the coy approach.
Be forewarned. Once you have given a command or correction, stick to it. IF you give in once, these dogs remember and will try to get away with the same thing a dozen times more. Corrections need only be as strong as the dog's behavior dictates. With some Bullmastiffs a strong "no" is sufficient. Others need firmer methods. Start with the least severe correction. The Bullmastiff only needs to know you mean what you say. ALWAYS BE CONSISTENT. Another warning; when you correct your dog, you may find you have a budding Hamlet on your hands. The Bullmastiff has a very expressive face and will use this expressiveness to make you feel just terrible for breaking his little heart by disciplining him. Keep looking into those eyes and you will find yourself driven to begging forgiveness to doing exactly what you should have done.
The Bullmastiff with a proper temperament should not be aggressive and guardy all the time. The lovely thing about this breed is that the dogs have a "live and let live" attitude. Unless something is wrong, you should not see these dogs in their working mode. The Bullmastiff is perfectly content to watch TV with the children, sleep on his back with his feet in the air, play with family members or other family dogs, or just find his favorite spot to lie down where he can get a clear view of the goings-on in the house or yard. The Bullmastiff can go from lying perfectly still, completely at ease, to moving full speed in a matter of seconds. If something needs his attention he'll be there. The Bullmastiff is very discriminating. He can tell who is legitimately on your property and who is trespassing. He knows the difference between someone you let into your house and someone trying to come in through a window or over a fence.
The Bullmastiff is a working dog, and as such should have good muscle tone and an alert mind. Mental stability is extremely important in a breed of this size. In choosing a puppy for the average family situation do not choose the most dominant and certainly not one that is shy. Since the breed as a whole is strong willed, the puppy with the middle of the road approach to life will be the most trainable and adaptable.
Speaking of training, consistent, firm, and kind training is a necessity. The Bullmastiff may have a mind of his own, and he is far from stupid. You just need to convince him that even though he thinks his way of doing things is better than yours, you are paying for the dog food so he's just going to have to humor you and do what you say.
The Bullmastiff is loyal and loving. He will give everything for those he loves. In return it is only fair for him to receive respect and love from those he lives with.