Jaime Lannister did not become king primarily because his lifelong vows as a member of the Kingsguard strictly prohibited him from holding lands, titles, or having heirs, thus precluding him from inheriting any lordship or making a claim to a throne.
The Sacred Vows of the Kingsguard
The Kingsguard is an elite order of knights sworn to protect the reigning monarch of the Seven Kingdoms. Upon taking their vows, members make profound sacrifices that directly impacted Jaime's potential for kingship:
- Forfeiture of Inheritance: Kingsguard knights are required to forsake all claims to lands, titles, and wealth. This meant Jaime could not inherit his family's ancestral seat of Casterly Rock or the Lordship Paramount of the Westerlands, which would have made him the most powerful lord in his region.
- Celibacy and Heirs: They swear off marriage and fathering children, ensuring their loyalty remains solely with the crown and preventing them from establishing competing dynasties.
- Lifelong Service: The vows are for life, meaning a knight serves until death, unable to abdicate their position for other pursuits, including a claim to a throne.
Preclusion from Lannister Titles
Due to these solemn vows, Jaime was specifically unable to inherit his father Tywin Lannister's vast lands and titles. This made his younger brother, Tyrion Lannister, the legitimate heir to Casterly Rock and the Lord Paramountcy of the Westerlands, a fact that greatly vexed their father. Jaime's position in the Kingsguard therefore removed him from any line of succession for regional power.
No Claim to the Iron Throne
Beyond his inability to inherit his family's titles, Jaime Lannister had no direct birthright claim to the Iron Throne of the Seven Kingdoms. He was a member of House Lannister, not of the royal dynasties that traditionally held the throne, such as the Targaryens or Baratheons. Even if circumstances had been different and a path to the Iron Throne opened for House Lannister, his Kingsguard vows would have prevented him from ever taking it, as his loyalty was sworn to the King, not to a personal ambition for the crown.
Summary of Reasons
The following table summarizes the key reasons why Jaime Lannister did not become king:
| Reason | Explanation |
|---|---|
| Kingsguard Vows | Upon joining, Jaime swore an oath to forsake all claims to lands, titles, and the right to marry or have heirs, dedicating his life to the crown. |
| Inability to Inherit | His Kingsguard oath explicitly prevented him from inheriting his father's lordship and vast wealth, making Tyrion the heir instead. |
| No Royal Lineage | As a Lannister, Jaime was not in the traditional line of succession for the Iron Throne by birthright, unlike the Targaryens or Baratheons. |
For more information on the Knights of the Kingsguard, you can explore resources like the Wiki of Westeros.
