An example of this is- what is the role of the Kingsguard in protecting the royal family? Are they beholden to the entire family, or the king alone? Well I think to some extent that depends on what the king says. We have examples of Mad King Aerys apparently raping his wife, and yet senior Kingsguard (and notably well- respected members) told Jaime to stand down.
"We are sworn to protect her as well." Jaime says to Ser Darry as they guard the bedroom
"We are, but not from him." replies Darry.
Also when Aerys has Brandon Stark and his father put to death in a particularly gruesome way, Jaime is advised by Hightower.
"You swore a vow to guard the king, not to judge him."
So here you have the great and noble knights, the ones Jaime and everyone looks up to, basically telling Jaime that the king can do whatever he wants. It's not for them to intervene. And maybe that's right, technically- but how ironic is it that Jaime wanted to act, and the great knights said no, when the great knights are lionized and Jaime is reviled?
It's also interesting that just as Jaime looked up to those great knights, years later he would appear to many as the epitome of what a knight should be. Here's what a young Jon Snow thinks the first time he sees Jaime.
They called him the Lion of Lannister to his face and whispered "Kingslayer" behind his back. Jon found it hard to look away from him.
Jaime at one point recalls the summer he was knighted for his actions against the Kingswood Brotherhood, a notorious outlaw band. He was a squire to the Kingsguard.
And he'd held his own against the Smiling Knight, though it was Ser Arthur who slew him. What a fight that was, and what a foe. The Smiling Knight was a madman, cruelty and chivalry all jumbled up together, but he did not know the meaning of fear. And Dayne, with Dawn in hand... the outlaw's longsword had so many notches by the end that Ser Arthur had stopped to let him fetch a new one. "It's that white sword of yours I want," the robber knight told him as they resumed, though he was bleeding from a dozen wounds by then. "Then you shall have it, ser," the Sword of the Morning replied, and made an end of it.
The world was simpler in those days, Jaime thought, and men as well as swords were made of finer steel. Or was it only that he had been fifteen? They were all in their graves now, the Sword of the Morning and the Smiling Knight, the White Bull and Prince Lewyn, Ser Oswell Whent with his black humor, earnest Jon Darry, Simon Toyne and his Kingswood Brotherhood, bluff old Sumner Crakehall. And me, that boy I was... when did he die, I wonder? When I donned the white cloak? When I opened Aerys's throat? That boy had wanted to be Ser Arthur Dayne, but somplace along the way he had become the Smiling Knight instead.
The other thing I want to look at with the Kingsguard is their actions at the Tower of Joy. This is where three Kingsguard stood against seven as Ned Stark came down to rescue his sister Lyanna. There is some disagreement as to whether Lyanna was taken by Rhaegar or went with him- regardless Rhaegar was away fighting Robert and three of the greatest Kingsguard were left to guard her. Even from her brother? These three were Ser Arthur Dayne, Ser Gerold Hightower and Ser Oswell Whent.
"I came down on Storm's End to lift the siege," Ned told them, "and the Lords Tyrell and Redwyne dipped their banners, and all their knights bent the knee to pledge us fealty. I was certain you would be among them." "Our knees do not bend easily," said Ser Arthur Dayne.
"Ser Willem Darry is fled to Dragonstone, with your queen and Prince Viserys. I thought you might have sailed with him."
"Ser Willem is a good man and true," said Ser Oswell. "But not of the Kingsguard," Ser Gerold pointed out. "The Kingsguard does not flee."
"Then or now," said Ser Arthur. He donned his helm.
"We swore a vow," explained old Ser Gerold.
"And now it begins," said Ser Arthur Dayne, the Sword of the Morning. He unsheathed Dawn and held it with both hands. The blade was pale as milkglass, alive with light.
"No," Ned said with sadness in his voice. "Now it ends."