Irish Wolfhound history is believed to go back as far as 9,000 years to 7000 B.C. Other theories state that the breed was introduced to the British Isles around 3000 B.C. when Phoenicians sailed in for trading and their sighthounds were crossed with regional mastiffs.
While the jury is out on the actual Irish wolfhound origin, there is far more solid evidence that the dogs were present in the Isles around 270 B.C. At that time, they were apparently used on the continent for war. When Celts sacked Delphi, the men had the dogs alongside them to fight. A century later, these accounts were noted by Julius Caesar when he penned a treatise called The Gallic Wars.
In the 5th century A.D., Irish laws and literature made mention of the dogs as "cú," which can be translated as "hound" or "wolf dog." In time, these dogs were trained for hunting and as guard dogs. The term "Cu" became a prefix that was bestowed upon warriors and kings who were to be respected, and the myth of Cúchulain reflects this. The Irish hero of the Ulster Cycle tales slew the hound of Culain and then took up the position of guarding the house that the formerly fearsome dog previously protected.
During the Tudor conquest of Ireland in the 1500s, the Irish Wolfhounds were legally owned only by nobility. A description of the breed can be found in the 1571 book titled Historie of Ireland by Saint Edmund Campion. In 1652, Oliver Cromwell made a declaration meant to protect the number of Irish Wolfhounds.
In the 18th century, the Wolfhounds had become scarce. In his 1790 book A General History of Quadrupeds, Bewick writes that they are the biggest and most beautiful dogs of all known dog breeds. In 1796, was when the allegedly last wolf in Ireland was killed. The dogs thereafter were used less as hunters than as status symbols.