The descent of Castamir from the Royal House of Gondor, showing his relationship to Eldacar, the rightful King whose throne Castamir usurped for ten years between III 1437 and III 1447.
A Gondorian noble, the great-grandson of the KingCalmacil. When Eldacar became King in Gondor, there was popular unrest because his mother Vidumavi belonged to the Northmen, and so he carried only half-Gondorian blood. Castamir took advantage of this unrest to launch a rebellion, and he succeeded in deposing Eldacar, who fled into exile. For ten cruel years he ruled Gondor, but Eldacar the rightful King built an army in exile, and returned to oust Castamir and reclaim his throne.
Notes
1
The date of Castamir's birth appears only in The History of Middle-earth volume XII, The Peoples of Middle-earth. It cannot therefore be considered completely reliable.
2
Castamir's name is nowhere explained, and the first element Casta- is difficult to identify. The only realistic possibilities from known Elvish name elements would probably be kas 'head' or kassa 'helmet', though these are uncertain interpretations. The final -mir is 'jewel', a relatively common name ending among the Dúnedain of Gondor.