Éomer blev konung efter Théodas död (betoning min):
Then a minstrel and loremaster stood up and named all the names of the Lords of the Mark in their order: Eorl the Young; and Brego builder of the Hall; and Aldor brother of Baldor the hapless; and Fréa, and Fréawine, and Goldwine, and Déor, and Gram; and Helm who lay hid in Helm’s Deep when the Mark was overrun; and so ended the nine mounds of the west-side, for in that time the line was broken, and after came the mounds of the east-side: Fréalaf, Helm s sister-son, and Léofa, and Walda, and Folca, and Folcwine, and Fengel, and Thengel, and Théoden the latest. And when Théoden was named Éomer drained the cup. Then Éowyn bade those that served to fill the cups, and all there assembled rose and drank to the new king, crying: 'Hail, Éomer, King of the Mark!'
Return of the King Book VI Chapter 6: "Many Partings"
Även om det är värt att notera att Éomer faktiskt är Théodos brorson, inte hans son. Théodas son var Théodred, som dog utanför skärmen (eller utanför sidan) under händelser av Riksförbundet
Det är bara en gång jag kan tänka på var det skulle vara vettigt att säga att Éowyn lyckades Théoden som kung (väl, drottning), och det är i Två Torn när både Théoden och Éomer lämnar Helm djup:
'Behold! I go forth, and it seems like to be my last riding,' said Théoden. 'I have no child. Théodred my son is slain. I name Éomer my sister-son to be my heir. If neither of us return, then choose a new lord as you will. But to some one I must now entrust my people that I leave behind, to rule them in my place. Which of you will stay?'
No man spoke.
'Is there none whom you would name? In whom do my people trust?'
'In the House of Eorl,' answered Háma.
'But Éomer I cannot spare, nor would he stay,' said the king; 'and he is the last of that House.'
'I said not Éomer,' answered Háma. 'And he is not the last. There is Éowyn, daughter of Éomund, his sister. She is fearless and high-hearted. All love her. Let her be as lord to the Eorlingas, while we are gone.'
'It shall be so,' said Théoden. 'Let the heralds announce to the folk that the Lady Éowyn will lead them!'
The Two Towers Book III Chapter 6: "The King of the Golden Hall"
Men, som framgår av ovanstående konversation, valdes hon att leda bara för att Éomer, kungens utnämnda arving, var i krig. Vi kan föreställa oss att, om Éomer hade dödats i Pelennors slag, skulle Éowyn ha stigit till tronen.