Guy de Lusignan 

Come on Adam, I was surprised by your edit. It's clearly Guy de Lusignan. Even the English statue in Damascus uses the "de". Only 900 v. 700 on google books admittedly, but it's more when it only includes the name as a surname. How will anyone know it's a hereditary name if you use "of"? Even English earls keep their "de" untranslated.  (Talk)