If you're interested in the family and want more detail on their 630-year history, the 23rd Vans (in direct descent from the first Vans of Barnbarroch in 1384) and current holder of the title and coat of arms, Jamie Vans, has just self-published an updated book about the family and some of his more notable ancestors and their involvement in history right up to present day.
The book is available for sale on Blurb UK at this link: http://www.blurb.co.uk/b/9171011-a-personal-history-of-my-family-i. in PDF, Kindle and hardcopy formats.
We know that today many North American and Australian lines of Vances descend from the same original family as the Vans of Barnbarroch - this is Group 1 (both 1a and 1b) of the Vance DNA Project. But it is also the possible origin of the surname for any of us as well whose ancestors were Irish or Scottish.
A wonderful reference for anyone with an interest in the Barnbarroch Vans family!
