So they formed the brotherhood, and one midnight swore eternal fealty.

He could say nothing to console her, plead as he might, assume the blame, and swear eternal fealty.

In their letters they had already sworn eternal fealty; now they were to see each other face to face.

Twenty tribes had joined the federation, and their chiefs had sworn eternal fealty to one another and to me.

Not only that, but I'd probably have sworn eternal fealty to them for their service even though I could not stand their way of thinking.