I was hoping the EuroAristo proj. could help determine the correct spelling of the Earls/Dukes of Lennox and their descendants last name as 'Stuart' instead 'Stewart'.
In the Complete Peerage 1st ed v.4, pp.63-67 Cokayne has the surname for the Darnley branch with the surname spelled 'Stuart' starting with Matthew Stewart-1359, the 2nd Earl. His father John has both names. The CP has all the future Earl/Dukes of Lennox, which includes King James VI/I, spelled Stuart.
It is confusing with the 1st-4th Earl that they all married into the Scottish Royal Family, and that branch seems to prefer 'Stewart'.
I checked VIAF (The Virtual International Authority File) and the first Lennox Stuart that appears is his grandson Matthew Stuart, 4th Earl of Lennox and grandfather of King James VI/I, spelled 'Stewart'
His son Henry, Lord Darnley father of King James VI/I is spelled 'Stuart'. Stuart and all the other Lennox were spelled that way that I saw.
There's some othere G2G questions about this spelling difference in general in Scotland but I am of the opinion this particular family should be 'Stuart'. Many of the descendants of Matthew have either Stewart or both Stewart and Stuart, which could be correct with a citation but the LNAB probably should be changed to Stuart. I hoped with a consensus that would make this a little easier or clear and assist making the change. Perhaps someone has a good reference for this name other than a peerage source since this is a pretty notable family. Thanks for your help!