Descended from the medieval Earls of Lennox, the MacFarlanes occupied the land forming the western shore of Loch Lomond from Tarbet up-wards.

The nineteenth-century Scottish antiquary George Chalmers, in his Caledonia, quoting the twelfth century English chronicler Symeon of Durham, wrote that the original Earls of Lennox descended from an Anglo-Saxon – Arkil, son of Egfrith.

[4][5] These two views are not mutually exclusive, as what is now southern Scotland and northern England had, in the post-Roman and early Mediaeval era, been a flux of Gaelic, Brittonic, Scandinavian and Germanic ethnicities.

There is no contemporary evidence of this Parlan or his elided father, only centuries-retrospective assertions that private documentation existed at the time of the Macfarlane attempt to claim the defunct earldom of Lennox.

[7] In 1544, Mac Pharlain led three hundred of his men, and joined Lennox and Glencairn at the Battle of Glasgow Muir, where they were narrowly defeated.

The sixteenth century, English chronicler, Raphael Holinshed described this MacFarlane force as follows: "In these exploytes the Erle had with him Walter McFarlane of Tarbet, and seven score of men of the head of Lennox, that spoke both Irishe and the English Scottish tongues very well, light footmen very well armed in the shirtes of mayle, with bows and two-handed swords; and being joined with the Scottish archers and shotte, did much avayleable service in the streyghts, marishes, and mountayne countries".

[7] The clan, led by Duncan's son, Andrew, fought under the Regent James Stewart, 1st Earl of Moray, against the forces of Mary, Queen of Scots, at the Battle of Langside in 1568.

[7][10] The clan's part in the battle is related to by Holinshed: "In this battayle the vaiancie of an Hie-land gentle-man named M'Farlane, stood the Regent's part in great steede; for in the hottest brunte of the fight, he came in with three hundred of his friends and countrymen, and so manfully gave in upon the flanke of the queen's people, that there was great cause of the disordering of them".

[9] After the battle, the clan also boasted of capturing three standards of the Queen's army, which were preserved as trophies for a long time afterwards.

[9] For his clan's aid, Andrew was awarded the crest of a "demi-savage proper, holding in his dexter hand a sheaf of arrows, and pointing with his sinister to an imperial crown, or, with the motto, This I'll defend", by the Earl.

The heir of line then passed to his sister, Jane Watt MacFarlane, who was born in 1817 and who married a Mr James Scott and settled in Sunderland, England.