_Robert III of ROS ___
                                            |                      
                       _William of ROS _____|
                      |                     |
                      |                     |_Isabella of DUNKELD _+
                      |                       (1165 - ....)        
 _William of ROS _____|
| (.... - 1310) m 1268|
|                     |                      ______________________
|                     |                     |                      
|                     |_Lucy FITZPIERS _____|
|                                           |
|                                           |______________________
|                                                                  
|
|--Ivetta of ROS 
|  (1285 - 1331)
|                                            ______________________
|                                           |                      
|                      _____________________|
|                     |                     |
|                     |                     |______________________
|                     |                                            
|_Eustache FITZRALPH _|
   m 1268             |
                      |                      ______________________
                      |                     |                      
                      |_____________________|
                                            |
                                            |______________________