Take a look at this.
Charles Seper writes:
This is now on the web. Have fun, as I did, reading CSL's origins!
Silas McCaslin's mother corresponded with Lewis over many years, and several
of Lewis' letters to her have appeared in books of his collected letters.
Silas and his brother Alston (both dentists from Georgia in
their late 60's) have compiled an incredibly comprehensive manuscript
pertaining to the Lewis family line going as far back as the mid 16th
century. They give not only names and dates, but as much information
as they could find on each individual in the Lewis lineage. I've
placed a link to it on the C.S. Lewis page of my own MacDonald site
but wanted to leave it here with you as well since I know that most of
you have an interest in Lewis.
The website of Alston and Silas McCaslin:
http://www.silasdobbsmccaslin.com/
And a direct link to their 55-page manuscript:
http://home.comcast.net/~smccaslin2/AncestryofC.S.Lewis.html
This from my friend Chuck who runs and maintains
http://georgemacdonald.info/
There is much there including videos you'll and links. Spend some really
enjoyable time perusing this site!
Blessings,
Ann