In the ancient Celtic tongue, a ros became defined as a promontory, such as the fertile land between the Cromarty and Dornoch Firths. Easter Ross emerged as the stronghold of Clan Ross, and it is believed that the first Earl, Malcolm Macbeth, who lived in the early twelfth century, allied his family to O'Beolan of the great Irish royal house of Tara, by the marriage of his daughter to an O'Beolan priest. The clan was sometimes also referred to as Clan Anrias, alluding to Anrias or Andrew, supposedly a distinguished O'Beolan ancestor. However, a charter from William O'Beolan (fifth Earl of Ross in that line) to a cousin Paul MacTire, is mentioned in a manuscript of 1450 and it indicates that both the O'Beolans (the progenitors 0f Clan Ross) and Clan Gilleanrias (Servant of Andrew, commencing with Paul MacTire) are traced back to Gilleon na h'Airde (Collin of Aird) who lived in the tenth century. Even the latter origin might more truthfully be said about the O'Beolan earls rather than the general clan members. Thus, the O'Beolans, Gillanders and Rosses came to be associated with an ancestor who was a follower/servant of St. Andrew, Scotland's patron saint.

Fearchar Mac an t'Sagairt (Farquhar Macintagart) was made a Norman knight in 1215 "on the seventeenth day before the Kalends of July" for slaying enemies of King Alexander II during a rebellion in the north. He seemed more than willing to toss out the ancient clan system in favour of a feudal system, for which his price was a Norman Knighthood, the first in the Highlands. While a guest of the English king, Fearchar was challenged to a knightly combat by a French courtier renowned for his prowess with sword and lance; Fearchar agreed to show what a Ross-shire Highlander was made of and he won quite handily.

Fearchar, of the O'Beolan line in Wester Ross apparently earned his right to the lapsed title of Earl in 1234 through his mother (in the old Pictish tradition which was retained as the rule for Scottish dignities). As a warrior knight, he quickly earned the favour of the king. One reference, pertaining to the earliest Earls of Ross in CLANS, SEPTS AND REGIMENTS OF THE SCOTTISH HIGHLANDS by Frank Adam, 1970, notes: "During the Royal campaign in Galloway, material aid was rendered to the king by Farquhar Macintagart (sic), SECOND Earl of Ross. In recognition of the Earl's services he received a grant of land in Galloway ...". It is also most noteworthy that one finds many people with the surname of Ross, whose origins and religion (unaffected by the Protestant Reformation) may be traced to this land grant in the South-West of Scotland. The adoption of Clan surnames has been attributed to the encouragement by King Malcolm III (Canmore) well over one hundred years earlier.

Fearchar's wife was allegedly Margaret MacGillvray in the family of Somerled. Their offspring were William (third Earl of Ross), Malcolm de Ross (drowned at 18 years), Euphemia and Christina. During his lifetime Earl Fearchar/Farquhar was given lordship rights over lands in Ross, Skye, Lewis and Moray. He died in his Castle of Delney in 1251 and was buried in Fearn Abbey which he built.

William, the third Earl of Ross, became one of the most important Scottish nobles during the reign of King Alexander III. Together with other Scottish nobility, William vowed to maintain and defend Princess Margaret's title to the Crown of Scotland if Alexander III should die without a son. He commanded one wing of the Scottish army during the defeat of the Viking fleet under the command of King Haakon of Norway in 1263, for which he was given the title "Lord of Skye and Lewis". Earl William of the O'Beolan line died at Erles-Allane in 1274.

William, the fourth Earl of Ross, succeeded his father in the O'Beolan line. When Margaret the Maid of Norway died, there was a dispute over the right of succession to the Scottish throne. King Edward I of England made Scotland an English dependency, and chose John Balliol over Robert the Bruce and eleven other claimants. The Scottish Highlands approved this decision at first, but in 1296 the army of Scotland rose up against King Edward I, and eventually the earls were imprisoned in the Tower of London. William's wife, Euphemia Countess of Ross, persuaded the king to release William and appoint him as Warden of Scotland beyond the River Spey.

In 1306, Robert the Bruce was crowned King of Scotland at Scone, and he was the reigning monarch at the time Earl William was released from the Tower. King Robert the Bruce had placed his wife, Lady Elizabeth de Burgh and his stepdaughter Lady Marjory in the sanctuary of St. Duthac's Church at Tain. William seized both of them to satisfy his duty to the English King and to preserve his titles. King Robert the Bruce retaliated by invading Ross and Sutherland in the following year. William sought the King's pardon and swore an oath of fealty, which was cemented by the marriage of William's eldest son Hugh to Princess Maud, one of the King's sisters. Eventually, the Earl William was granted the Castle and Estates of Ferncrosky (Croick) and the Great Castle of Dingwall was returned to the possession of the Earls of Ross.

In 1309, William of Ross and the Earl of Sutherland, his former ward, were the only two earls present at the first Parliament held by Robert the Bruce. He led the men of Ross, Sutherland and Caithness at the Battle of Bannockburn in 1314, where his youngest son Sir Walter de Ross was killed. William was also one of those who addressed the famous Declaration of Arbroath to the Pope stating Scotland's right to independence. Aside from Hugh and Walter, the remaining offspring were John, Isabella and Dorothea. The "Kalendar of Fearn" states that Earl william died at his Castle of Delney on January 28, 1322.

Hugh became the fifth Earl of Ross in 1322. He was made Sheriff of Cromarty, and received royal charters from King Robert I (Robert the Bruce) to the lands of Rarichies, the Isle of Skye, Strathglass, Strathconon and others.

His first marriage (Lady Maud), produced two sons (William the next Earl of Ross and John de Ross d. 1364) and one daughter (Marjory). His second marriage (Lady Margaret Graham) produced a son (Hugh "of Rarichies" from whom the chiefs of Balnagowan are descended) and two daughters (Euphemia and Janet). [King Robert II married, as his second wife, Euphemia, who was then crowned Queen of Scotland in 1371.]

Earl Hugh, the great-grandson of Fearchar Mac an t'Sagairt, was killed in 1333 at the battle of Halidon Hill near Berwick along with many of the leading barons of Scotland. It is said that Earl Hugh wore the shirt of St. Duthac, which would render him invulnerable to the enemy. The English general, William Douglas, removed the shirt from the Earl's body and returned it to the sanctuary of St. Duthac at Tain.

William, the eldest son of Earl Hugh and Lady Maud Bruce, became the sixth Earl of Ross when he returned from Norway in 1336, three years after his father's death. He assisted Robert, the High Steward of Scotland and Governor of the Kingdom, for which he was made "Justiciar of Scotland benorth the Forth" and held the title "Lord of Skye".

Ten years later, King David II assembled the barons of Scotland and their armies to invade England. King David II had recently restored properties in North Argyll to Reginald of the Isles, and Earl William of Ross took the opportunity to revenge himself over the disputed lands. Deserted by the armies of Earl William and the deceased Reginal, King David II pressed on and was captured during the Battle of Durham in 1346. In 1350, with the approval of his sister Marjory, William appointed his brother Hugh as heir to the Earldom of Ross (upon condition of the king's consent).

Earl William and his wife Mary (daughter of Angus Og of the Isles) had a son (William, who died in 1357) and two daughters (Euphemia and Joanna).

After an eleven-year confinement in the Tower and a further nine-year refusal by the northern lords to pay his huge ransom, King David II caused Earl William to forfeit all of his lands in 1370, and the Earldom of Ross was given to his daughter Euphemia and her husband Sir Walter Leslie following the death of Earl William in 1372 at the Castle of Delney. The lands of Balnagowan remained in the possession of the designated heir, Hugh of Rarichies, who became the first Chief of Clan Ross in the Balnagowan line. [The ordering of the O'Beolan Earl's of Ross in many of the early clan summaries ignore Malcolm Macbeth who was the first Earl of Ross. Thus, I have adopted the new convention which is less confusing.]

The Earls of Ross after the O'Beolans were the Leslies, Sir John Stewart, (an annexation of the title by James I from 1424 until 1427), the MacDonalds, and a forfeiture of the title to the crown in 1476 until Henry Stewart, Lord Darnley was created Earl of Ross in 1565 by Elizabeth I of England. Insofar as the Clan Ross history is concerned, these later Earls were peripheral to actual events involving the clansmen.

The O'Beolan Earls of Ross gained the earldom in almost the same manner in which they lost it ... the ancient transference of title through a female. Theirs is a history of flip-flops in terms of convenient alliances and loyalties. Most Clan Ross historians affirm that these five earls were the first five chiefs of the clan, but it has been documented already that Clan Ross existed before any of the O'Beolan Earls of Ross. In fact, the land of Ross was in records, which preceded both the clan and the earls. The era of the initial chiefs was marked by their powerful involvement in Scottish history, even though a belief in the supernatural powers of the shirt of St. Duthac perhaps contributed to the demise of one of them.