The range of size, shape, color, personality and purpose for which dogs are bred is jaw-dropping. Over centuries, different dogs in different geographic locations have been honed by humans to play certain roles, from hunter to guardian, from herder to companion.
For some of these breeds, size has been a significant player in the search for perfection, whether that was to hunt bigger or faster game or guard a home with more intimidation, or even just to have the mass to survive in freezing locations. Of the hundreds of dog breeds around the world, here are nine of the largest.

1. Great Dane

A great dane sits on a couchOn average, Great Danes stand around 28-30 inches tall. (Photo: Elsa Hoffmann/Shutterstock)
We'll start with the breed that is widely recognized as the largest, at least in terms of height. The Great Dane is a breed of German origin and its German name of Deutsche Dogge, means German mastiff. However, before setting down official roots in Germany, the dogs that eventually became the Great Dane breed came from a crossbreed between English mastiffs and Irish wolfhounds.
Though they aren't the heaviest dogs, reaching around 100-120 pounds, they are among the tallest. The average Great Dane stands around 28-30 inches tall but often they can be taller. The world record holder for tallest dog was a Great Dane named Zeus who stood an astounding 44 inches tall. However, these big dogs trade longevity for their size, and live only to be between 6 to 8 years old. Zeus died of old age at just 5 years old.
Though the Great Dane is typically considered the largest of all dog breeds, we're going to look at a few other breeds that give this one a run for its money, including one breed that is actually even taller.
A small dog stands under a Great DaneFor a better understanding of its height, this Great Dane poses with a small dog standing under her. (Photo: Dmussma/Shutterstock)

2. Neapolitan mastiff

A Neapolitan MastiffThis breed comes in several colors including black, blue, mahogany and tawny. (Photo: Stanimir G.Stoev/Shutterstock)
Mastiff breeds are certainly among the largest dogs in terms of sheer mass. The Neapolitan mastiff originated in southern Italy. Used as a guard dog, the average male mastiff stands between 26-31 inches tall and weighs a hefty 130-155 pounds. Females are usually a little smaller, standing a few inches shorter and weighing 110-130 pounds.
This breed is known for being fearless and protective of home and family, making it an ideal guard dog — but not an ideal warning system. Mastiffs tend to be quiet, and are known for sneaking up on intruders rather than barking to warn them off. Because of the breed's protective nature, you certainly don't want to stand between these dogs and their family, which makes this dog a breed only for owners well versed in dog training and able to put in the extensive time needed for socialization.

3. Scottish Deerhound

A deerhound stands in a fieldBuilt similar to a greyhound but heavier, the deerhound breed is meant for speed. (Photo: Adam Singer/flickr)
Going back to the leggy breeds, the Scottish deerhound gives away its purpose and origin in its name. Originating in Scotland well before recorded history, the breed is a courser, once used to hunt red deer and easily chasing down its prey. They are larger and heavier than greyhounds but are built similarly, with a lanky body meant for speed.
Deerhounds can stand as tall as 32 inches and weigh as much as 110 pounds. Though they aren't used for deer hunting today, the breed is kept alive by enthusiasts who use them for show and in some places, lure coursing.
A trio of deerhoundsThe deerhound requires a great deal of exercise, especially when young. (Photo: Adam Singer/flickr)

4. Dogue de Bordeaux

A trio of Dogue de BordeauxYou may recognize this mug. The Dogue de Bordeaux was the breed of dog that starred across from Tom Hanks in the film 'Turner and Hooch.' (Photo: otsphoto/Shutterstock)
The Dogue de Bordeaux goes by several other names, including the Bordeaux mastiff, French mastiff and Bordeauxdog. But this breed, by any other name, still stands as massive. Though other breeds, from the poodle and French bulldog to the Great Pyrenees and Basset hound may be more famous breeds of French origin, the Dogue de Bordeaux is one of the most ancient breeds of France.
The Dogue de Bordeaux stands between 23-27 inches tall and weighs between 125-150 pounds. But though it is fairly average as far as mastiff breeds go, it does have one thing that sets it apart: It is reported to have the largest head of any canine in relation to body size.
Unlike the Neapolitan mastiff, the Bordeauxdog has been used for more than simply guarding house and home, though that was also in its job description. These dogs also were used for everything from watching over flocks to pulling carts. It has historically been a true working dog and a jack of all trades — at least, as far as dogs go. The breed is active and energetic outdoors, but once inside is, well, mellow to say the least.
Dogue de Bordeaux sleep on a bedIf you're a Bordeauxdog owner and wondering if you should let your pet sleep on the bed, the answer is: Only if you don't mind sleeping somewhere else. (Photo: Vitaly Titov & Maria Sidelnikova/Shutterstock)

5. Newfoundland

A newfoundland dog stands next to a creekWith heavy bones and big muscles, the Newfoundland is a powerful swimmer and a great water rescue dog. (Photo: Yan Wen/Shutterstock)
The Newfoundland is a working dog from, you guessed it, Newfoundland. Unlike many larger breeds, the Newfie wasn't bred to be a guard dog. Instead, its purpose was originally to help fishermen. The big, muscular dogs are able to haul nets and lines from boats, pull carts and, most importantly, fetch anything that falls overboard, including people. The breed is an exceptional water dog and strong swimmer, and there have been many rescues of people out at sea credited to these big, gentle-natured dogs.
Newfoundland dogs stand between 27-30 inches tall and weigh as much as 150 pounds. They look even bigger because of their thick double coat, which keeps them warm even in icy water.

6. English mastiff

An English Mastiff walks through lawnEnglish mastiffs have set the record for heaviest dog ever recorded. (Photo: Kachalkina Veronika/Shutterstock)
The English mastiff is enormous. Growing to a height of 30 inches, these dogs can weigh as much as 250 pounds. As a Great Dane holds the record for tallest dog, an English mastiff holds the record for heaviest. The biggest weight for a dog ever recorded was an English mastiff named Aicama Zorba, who weighed in at 343 pounds.
Their size is a significant part of the breed's past purpose, which included blood sports such as baiting bears, bulls and lions. Today, however, they are simply gentle giants, letting those courageous and fearless aspects of the breed's temperament sit on the back burner while the mellow, even-tempered and loyal sides come forward. They can make excellent family dogs as they are so easy-going. So if your kids are asking for either a dog or a pony, well... it's not like size should factor into your decision:
A mastiff stands next to a miniature ponyAs size goes, these dogs need about as much room as a miniature horse! (Photo: Kachalkina Veronika/Shutterstock)

7. Saint Bernard

A Saint Bernard stands in a lawnSaint Bernards are big, fluffy and easy-going companions. (Photo: Rita Kochmarjova/Shutterstock)
The Saint Bernard of brandy-toting fame is a breed originally created in the Swiss Alps and northern Italy as a rescue dog. The monks of the Saint Bernard Hospice are credited with training dogs for rescue and for playing a role in developing the breed we know today. Dogs can stand between 25-30 inches tall and weigh anywhere from 140 to 180 pounds.
Though they were originally used as rescue dogs to find and save travelers, today's Saint Bernards are mostly family dogs. They are famous for being gentle, loving, friendly and great with children. They are also apparently great with kittens, too:
A Saint Bernard cuddles with kittensSaint Bernards are known for their gentle giant nature. (Photo: Rita Kochmarjova/Shutterstock)

8. Leonberger

A Leonberger stands on a lawnA cross of three breeds created the beautiful Leonberger. (Photo: Mikkel Bigandt/Shutterstock)
If the Leonberger reminds you of a Newfoundland mixed with a Saint Bernard, it should. That's exactly how the breed originated. In the mid-1840s, Heinrich Essig of Leonberg, Germany, crossed a Newfoundland with a Saint Bernard for four generations, then added in a Pyrenean Mountain Dog to the mix. The result of these several generations of breeding is the Leonberger.
This breed stands between 27-31 inches tall and can weigh as much as 170 pounds. But despite their size, they are simply giant family dogs. Though their main purpose is as a companion animal, the breed does very well in everything from water rescue to tracking to herding. If it is an activity that requires both strength and smarts, the Leonberger is probably going to be good at it.

9. Irish Wolfhound

An Irish wolfhound stands on a lawn during a canine competitionThe Irish wolfhound is an ancient breed dating back many thousands of years. (Photo: Marcel Jancovic/Shutterstock)
Like the Scottish deerhound, the Irish wolfhound was bred to be a courser, and was indeed originally used to chase down wolves. Developed from war hounds into a dog used for hunting and guarding, the Irish wolfhound is ancient and may have been brought to Ireland as far back as 7000 B.C. Though their primary use was hunting, today's dogs are fairly quiet and reserved, intelligent and easygoing.
This breed is the tallest of all dogs, even the Great Dane. According to breed standards, the minimum height should be 32 inches for males and 30 inches for females. That's just the minimum. Males often stand as tall as 34-35 inches and weigh upwards of 140 pounds.
And though the English mastiff is as tall as a miniature horse, the Irish wolfhound is equal to a donkey.
A wolfhound stands next to a donkey