Dogs have been man's faithful companion for generations, centuries, millennia... just for far back our relationship with our canine friends goes truly is amazing.

When excavating ancient Roman cities, archeologists have found clay mosaics over the doors of homes and other buildings. The words these mosaics form include, Beware of the Dog.

The Romans also gave us one of the most commonly used names for a dog -- "Fido" comes from the Latin word meaning "fidelity".

Cats aren't the only animals that have been held sacred by ancient cultures. In the Far East, dogs -- particularly the Pekingese -- were held in such high regard that some had their own servants and bodyguards. Many temples had dogs installed in positions of high honor. One of the most honorable occupations of ancient China was that of the dog trainer.

In the Chinese zodiac, those born under the sign of the Dog are thought to be particularly compassionate and loyal. The Aztecs and the Mayans also assigned the dog a position in their zodiac; those born on the days of the dog were believed to make the most effective leaders.

One dog has even achieved sainthood. A 13th century French knight killed his loyal greyhound Guinefort, thinking the dog had killed his son. It was only after the dog was dead that he found his son, alive and well, and the remains of the snake that Guinefort had not only killed, but saved his son from.

Archaeologists have discovered cave paintings of dogs accompanying early man, suggesting that fire, the wheel and domesticated dogs all went hand in hand.

Ancient Egyptians were fiercely devoted to their canine companions. Written records have yielded references to a number of pet dogs, and the loss of a beloved pet meant a long mourning process for his family.

The image of the St. Bernard as the devoted search and rescue dog is a popular one for a good reason. One of the most successful rescue dogs was a St. Bernard who patrolled the Swiss Alps in the early 1800s.

Dogs get a mention in the Bible 14 times. It's not the only holy book to mention canines, either. Zoroastrianism, an ancient Middle Eastern religion, has a religious text with an entire section devoted to how believers should treat their dogs.

In the Middle Ages, dogs were invaluable companions and served in a variety of ways. Dogs like the mastiff were often armored and sent to war alongside their masters, where they proved deadly against mounted soldiers. Merchants and tax collectors often had dogs that escorted them on their duties, and many people -- from the noble class to the peasants -- owned dogs for hunting.