_Piers de Lutegareshale ___+
                                            |                           
                       _Geoffrey FitzPiers _|
                      | (.... - 1213) m 1205|
                      |                     |_Maud _____________________+
                      |                                                 
 _John FitzGeoffrey __|
| (.... - 1258)       |
|                     |                      _Roger de Clare ___________+
|                     |                     | (1115 - 1173)             
|                     |_Aveline de Clare ___|
|                       (.... - 1225) m 1205|
|                                           |_Maud de St. Hilary _______+
|                                             (.... - 1195)             
|
|--Maud FitzJohn 
|  (.... - 1301)
|                                            _Roger de Bigod ___________+
|                                           |                           
|                      _Hugh de Bigod ______|
|                     | (.... - 1225)       |
|                     |                     |_Ida | Isabel Plantagenet _+
|                     |                                                 
|_Isabel de Bigod ____|
                      |
                      |                      _William Marshal __________+
                      |                     | (1146 - 1219) m 1189      
                      |_Maud Marshal _______|
                        (.... - 1248)       |
                                            |_Isabel de Clare __________+
                                              (1174 - 1220) m 1189