MS UCLA: collection 100: box 95
My dear Lady Mary
I am afraid I never heard of the name of Filian, unless it comes from the Scottish Saint Filam, St Fillan’s cave, Glenfillan. But that was a man, a Fifeshire abbot to whose good will the Scots attributed their victory at Bannockburn. At least so says Alban Butler and Baring Gould, and the latter gives as date 7th century, I cannot get nearer. Somehow I believe there was no capital F in old time and you know some Foulkeses spelt their name ffoulkes. Our F is only the first letter with the second being up inside.1 If there is a Scottish connection it might account for the Filian, but I once read that about the time of Henry III people took to indulging in fanciful invented names for their daughters, so it may have come from thence.
Yours sincerely
C M Yonge
A Gaelic scholar might tell you the meaning