Sir Rory Mor's Horn is a drinking horn, one of several heirlooms of the MacLeods of Dunvegan, chiefs of Clan MacLeod. Clan custom is that each successive chief is to drink a full measure of the horn in wine to prove his manhood. The artwork on the horn has been dated to the 16th century, and by some as far back as the 10th century. The MacLeod chiefs have several other notable heirlooms kept at Dunvegan Castle—such as the Fairy Flag and the Dunvegan Cup (pictured right).
Sir Rory Mor's Horn is a drinking horn, made of an ox's horn, tipped in silver. The rim around the mouth of the horn is thick and on this there are imprinted seven medallions. On three of the medallions are beasts, on three others are patterns, and on the seventh and joining medallion is both a pattern and a beast. R.C. MacLeod considered the work to be Norse, and declared the horn to date from the 10th century. The horn holds about 2 imperial pints (1.1 l). Clan MacLeod custom is that each successive chief, on achieving the age of manhood, should drain, in one draught, the horn which is filled to the brim. The horn is named after Sir Ruairidh Mòr MacLeòid (c.1562–1626), the 15th chief of Clan MacLeod.
There have been differing opinions concerning the age of the horn. In 1927, R.C. MacLeod declared his opinion that it dated from the 10th century. Professor Brögge, from Oslo, thought it was of Norse origin, dating from the 10th century. Professor Callander, from Edinburgh, considered it to be not unfamiliar with other objects of Scotland, and dated it to the 16th century.
In 1906, R.C. MacLeod noted that the greater proportion of the horn had been filled in, and that it was "but a moderate drink the present day Chiefs have to quaff. With what contempt, what might scorn would these stern warriors of the past look upon the puny performances of their descendants". In 1956, Elizabeth II and Prince Philip visited Dunvegan Castle. During this occasion, John, maternal grandson of the clan chief Dame Flora MacLeod of MacLeod, was challenged to quaff the horn which was filled with claret—which he did in one minute 57 seconds.