Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
STEUART
As described in historical dictionaries
Patronymica Britannica (1860)
STEUART. The Steuarts of Allanton, CO. Lanark (Barts.), are lineally descended from Alexander, sixth lord High Steward of Scotland, great grandfather of King Robert II., the first prince of the Stuart line. Courthope's Debrett.