_Alfonso V TRASTÁMARA _+
                                                     | (1396 - 1458)          
                           _Ferdinand I TRASTÁMARA _|
                          | (1423 - 1493)            |
                          |                          |_Maria of TRASTÁMARA __+
                          |                            (1401 - 1458)          
 _Alfonso II TRASTÁMARA _|
| (1448 - 1495)           |
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|                         |_Isabella of CLERMONT ____|
|                           (1424 - 1465)            |
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|                                                                             
|
|--Piero TRASTÁMARA 
|  (1472 - 1490)
|                                                     ________________________
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|                          __________________________|
|                         |                          |
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|                         |                                                   
|_Ippolita Maria SFORZA __|
  (1446 - 1488)           |
                          |                           ________________________
                          |                          |                        
                          |__________________________|
                                                     |
                                                     |________________________