The founder of the clan, according to legend, was a Thorkil (Torcadal) who was a member of the Scots army under Kenneth MacAlpin. The legendary story states that Alpin, father of Kenneth MacAlpin, was killed in battle, and his head was carried off by enemy Picts. Alpin's head was then displayed in the Pictish town of Camelon. The story goes on to state that the claimed ancestor of the McCorquodales, Thorkil, recovered recovered Alpin's head. For this deed, Thorkil was said to have been rewarded with lands on Loch Awe side. Be that as it may, the earliest record of the clan occurs in the 15th century. The Barons McCorquodale are recorded at this time, as holding sway over lands in Argyll, west of Loch Awe. They were centred at Phantelane (Anglicised from the Scottish Gaelic: Fionnt Eilean), or the "white island". Eilean-a-Bharain (from Scottish Gaelic: "the baron's island") was located in Loch Tromlee, on which their castle was located. Today the loch has been affected by drainage, the site of the castle ruins is no longer always an island. At one point in time, the entire shore of Loch Awe from Avich to Ard-an-aiseig was owned by the chiefs of the clan.
In 1434 Ewan, son of Ewan Makcorquydill received a grant of lands. In his charter, Ewan was described as "Lord of Maintelan". According to Black, this refers to "Phanteland". As time passed the McCorquodales of Phantelands became the most prominent family of McCorquodales. In 1542, the lands held by the Barons McCroquodale where incorporated into a free barony. In 1556, the seal of Duncan McCroquodale of Phantelane bore the legend, "S.duncan.mak.corkatill", which surrounded a shield with, a stag trippant couped halfway paleways. By 1612, Duncan was dead and his younger sons, Iain and Lachlan, were declared by the Privy Council as "notorious thieves and the supporters of Clan Gregour". These MacGregors who were wanted for many crimes, including the theft of a brown mare from the deceased Duncan. The barony passed from Duncan to his son, Duncan. According to Moncreiffe, this baron seems to have had sons by different wives, as the legitimacy of his heirs was "hotly disputed between the two litters". In the 17th century the clan supported the Campbells in the Civil wars.
In 1645, while campaigning, Alasdair MacColla and his men marched along the shore of Loch Tromlee. MacColla ordered his men to leave the castle and lands of the McCroquodales to be left un-molested. At the same time, Baron McCroquodale had his men standing to with orders not to fire. However, one of McCroquodale's men opened fire upon MacColla's men, and as a result one Macdonald clansman was killed. In retaliation MacColla ordered the the destruction of the island castle of the McCroquodales. Duncan McCroquodale of Phantelane was one of the Justices of the peace for Argyllshire, appointed in 1656 by Oliver Cromwell. In the 18th century, the last Baron McCorquodale to hold the clan lands around Loch Tromlee died, leaving the clan without a chief to this day. By the end of the 18th century there were McCorquodales living on Loch Aweside, who claimed to be descended from the legendary founder of the clan.