The Mastiff, or English Mastiff as they are sometimes known, is one of the most ancient breeds of dog. There are historic images of large, heavy dogs dating back to Egyptian times. Mastiff type dogs were used as war dogs in battle, and as estate guardians. The Mastiff we know today started developing in the 1800's, and is a much different dog than its ancestors, both in type and temperament.
The Mastiff is one of the largest breeds of dog, at least in regards to its weight, often reaching over 200 lbs, although around 130-175lbs is average. They come in a handful of colors, apricot, brindle, and fawn, but must always possess a black mask to go with it. You might be surprised to know that Mastiffs can also come in a longer coated variety called a "fluffy". It is a recessive trait that normally isn't seen, but will pop up from time to time in several breeds of Mastiff.
The Mastiff has a stable temperament overall. However, they do have a tendency towards protectiveness if not properly trained and socialized. They are typically calm and gentle and do well with children and other animals. Because of their size, they generally don't require much exercise and prefer to hang out with their owners at home. They are friendly toward accepted strangers, but aren't known to be attention hounds. Training should be done early so they learn to walk on a leash properly. Last thing anyone wants is to be dragged down the street by a potentially 200 lb dog!
They can be known to drool, so one may want to carry a "drool rag" with them so as wipe their face when needed. Health concerns associated with the breed consist of problems with their joints, heart, eyes, kidney, and cancer. As with all giant breeds, care must be taken not to overfeed. Not only can that cause growth problems when young, but can lead to bloat, and worsen any underlying joint or heart issues. Too much weight on an already big dog only harms the dog in the long run.