_Gilbert of CLARE ______+
                                               | (1180 - 1230)          
                        _Richard of CLARE _____|
                       | (1222 - 1262)         |
                       |                       |_Isabel MARSHAL ________+
                       |                         (1200 - 1239)          
 _Gilbert of CLARE ____|
| (1243 - 1295) m 1290 |
|                      |                        _John of LACY __________+
|                      |                       | (1192 - 1240)          
|                      |_Maud of LACY _________|
|                        (1222 - 1288)         |
|                                              |_Margaret of QUINCY ____+
|                                                (1208 - 1266)          
|
|--Gilbert of CLARE 
|  (1291 - 1314)
|                                               _Henry III PLANTAGENET _+
|                                              | (1207 - 1272) m 1236   
|                       _Edward I PLANTAGENET _|
|                      | (1239 - 1307)         |
|                      |                       |_Eleanor of BARCELONA __+
|                      |                         (1223 - 1291) m 1236   
|_Joan of PLANTAGENET _|
  (1272 - 1307) m 1290 |
                       |                        _Ferdinand III IVREA ___+
                       |                       | (1199 - 1252)          
                       |_Eleanor of IVREA _____|
                         (1239 - 1290)         |
                                               |_Jeanne of DAMMARTIN ___+
                                                 (1220 - 1278)