Not just tall but also burly, male Saint Bernards may measure 27 1/2 inches (70 centimeters) at the shoulder or taller, and may weigh upwards of 200 pounds (91 kilograms). But don't worry: A gentle disposition has been bred into these canine giants for centuries.
About a thousand years ago, Bernard de Menthon, an Augustine monk, founded a hospice in the Swiss Alps to help travelers passing through the dangerous passes. The ancient origin of the Saint Bernard breed is unclear, but the monks began using large dogs to help with rescues. The dogs developed a keen ability to find people buried in snow drifts, dig them out, lick them to revive them and even lie on them for warmth until help came. They also were good at predicting avalanches.
The dogs became so good at rescue that teams of two or three were sent out unaccompanied. If one found a stranded traveler, the other(s) would go fetch the monks [source: The Complete Dog Book -- please link to LMI].
Saint Bernards love their families. Like any large dog, they need ample exercise and a place to run. The longer-haired variety needs a good bit of grooming. And, as with any giant dog --even one that's been bred to be kind -- keep an eye on the dog when he's with small children. You don't want it to bowl the baby over, even with kindness.