_Gilbert of CLARE ___+
                                            | (1180 - 1230)       
                       _Richard of CLARE ___|
                      | (1222 - 1262)       |
                      |                     |_Isabel MARSHAL _____+
                      |                       (1200 - 1239)       
 _Thomas of CLARE ____|
| (1245 - 1287)       |
|                     |                      _John of LACY _______+
|                     |                     | (1192 - 1240)       
|                     |_Maud of LACY _______|
|                       (1222 - 1288)       |
|                                           |_Margaret of QUINCY _+
|                                             (1208 - 1266)       
|
|--Gilbert of CLARE 
|  (1280 - 1308)
|                                            _____________________
|                                           |                     
|                      _____________________|
|                     |                     |
|                     |                     |_____________________
|                     |                                           
|_Juliana FITZGERALD _|
  (1263 - 1300)       |
                      |                      _____________________
                      |                     |                     
                      |_____________________|
                                            |
                                            |_____________________