_Richard of CLARE ____+
                                            | (1153 - 1217)        
                       _Gilbert of CLARE ___|
                      | (1180 - 1230)       |
                      |                     |_Amice of GLOUCESTER _
                      |                       (.... - 1220)        
 _Richard of CLARE ___|
| (1222 - 1262)       |
|                     |                      _William MARSHAL _____
|                     |                     | (1146 - 1219)        
|                     |_Isabel MARSHAL _____|
|                       (1200 - 1239)       |
|                                           |_Isabel of CLARE _____+
|                                             (1172 - 1185)        
|
|--Isabel of CLARE 
|  (1240 - ....)
|                                            _Roge of LACY ________
|                                           | (1171 - 1211)        
|                      _John of LACY _______|
|                     | (1192 - 1240)       |
|                     |                     |_Maud of CLERE _______
|                     |                       (1175 - 1226)        
|_Maud of LACY _______|
  (1222 - 1288)       |
                      |                      _Robert II of QUINCY _
                      |                     | (1172 - 1217)        
                      |_Margaret of QUINCY _|
                        (1208 - 1266)       |
                                            |_Hawise of CHESTER ___+
                                              (1180 - 1241)