Per certain sources, holders of the surname Muir (also appearing as Mure and Moore), of Ayrshire, have been noted as a possible sept of Clan Boyd, though this is not clearly identified to a reliable resource.

The name is derived from the Scots form of the Middle English more, meaning "moor" or "fen".

Another version states that Gilchrist Mure was dispossessed of the house and living at Rowallan by the strong hand of Sir Walter Cuming, and was compelled to keep close in his castle of Polkelly until Alexander III raised sufficient forces to subdue Cuming and his adherents.

[52] The marriage of Robert and Elizabeth's daughter, Jean, to John Lyon, created the title Thane of Glamis.

His namesake was called the Rud of Rowallane, being large in stature, very strong and prone to pugilism; these characteristics neatly define the meaning of this archaic Scots word.

He wasted his inheritance and during his lifetime a protracted feud took place with the house of Ardoch (Craufurdland) which resulted in much bloodshed.

The 'Rud' resigned his lands in favour of his grandson John, who married Margaret Boyd a mistress of James IV.

[55] Sir Mungo Mure, credited with significant improvements to Rowallan, was killed in the Battle of Pinkie, in September 1547.

[56] Sir William Mure, (1594-1657), was also Laird of Rowallan, and was known for his contributions as a writer, politician, and a military leader, being wounded at the battle of Marston Moor, in 1644.

One of his granddaughters married Sir James Campbell of Lawers, third son of the Earl of Loudoun, who thus became Laird of Rowallan.

His only daughter's great-grandson, Charles Rawdon-Hastings, 11th Earl of Loudoun succeeded in 1874 and held the lands of Rowallan as Laird.

Muir/More/Moore/Mure are most prevalent in Ayrshire and areas in the Southwest lowlands, though branches had spread to Eastern Scotland as early as the 15th century.