The monks of Tibet must have been master dog breeders. They were able to work with the somewhat limited genetic pool available to them and fine-tune and finesse not just the Tibetan Mastiff, but also the Tibetan Spaniel, Tibetan Terrier, Lhasa Apso and Kyi Apso. Not only were they isolated from the rest of the world geographically, they were also cut off due to the politics of no contact with the western world. They persevered and to them we owe a debt for the Tibetan Mastiff.
While not a true mastiff, they are closer to the livestock guard dogs, such as the Great Pyrenees, than to Mastiff.
The Tibetan Mastiff is known as Drog-Khyi (འབྲོག་ཁྱི) in Tibetan, which means "nomad dog",("dog which may be tied", "dog which may be kept"). This name reflects their history as a guardian of livestock, villages, hones, temples and monasteries. The Tibetan nomads who also kept the Tibetan Mastiffs usually allowed them their freedom. The loyal Tibetan Mastiff did not stray far, as they took their job as guardian very seriously.
The Tibetan Mastiff or the TM as their friends call them, will sleep all day to be ready to patrol the property all night. Much like a Great Pyrenees, they patrol by barking. All. Night. Long. Sidebar: We listened to our Great Pyrenees, Zoe, bark all night for 11 years, until she passed at 13. We called it her, "Singing the bears away." Neither Steve nor I slept well for weeks after she passed, missing her voice.
In 2008, a genetic study proposed the Tibetan Mastiff split from wolves over 58,000 years ago and the next 12 oldest breeds split around 42,000 years ago. Truly making the Tibetan Mastiff THE oldest breed of dog.
It is said there are two types of Tibetan Mastiff, the Do-khyi which is a lighter, more active type and the Tsang-khyi. The Tsang-khyi, known as the monastery type, which is a bigger, heavier boned dog with more facial wrinkling.
It is known that the Tibetan Mastiff was the large guardian breed of Tibet. There are no written records, as you would expect. The Tibetan Mastiff is now considered one of the ancient breeds, as DNA evidence has now proven their definitive existence from that long ago.
The Tibetan Mastiff breeds are thought to have fought beside the Assyrian, Persian, Greek and Roman armies. Both Genghis Khan and Attila the Hun had Tibetan Mastiffs by their side.
The Tibetan Mastiff was allowed to develop as a more pure dog because of their isolation in the mountains of Tibet. And for that we are grateful.