[ANSTHRLD] Name usage

[Lynda Boots]

I have a client who wishes to use the name William de Thwenge (England, early to mid 1300).  Unfortunately, there was a William de Thwenge, brother to Marmaduke de Thwenge (http://www.genuki.org.uk/big/eng/YKS/ERY/Thwing/Thwing92.html)

Is he famous enough for this to be an issue?  Considering William was the fourth most common man's name in England for years, my client may run up against a famous William Anylastname.

Any suggestions?

Thanks.

Dreda
Halberd Pursuiviant