┌─William Trian
Robert Trian
│ ┌─Robert Pantulf ⇒
│ ┌─Ivo Pantulf
│ ┌─Hugh Pantulf
└─Joan Pantulf
│ ┌─Alan fitz Flaad ⇒
│ ┌─William Fitz Alan
└─Christina Fitz Alan
└─Christiana