Spoilers for the whole series. The overview is spoiler free; facts that give away later events stay folded under the book that reveals them.
Brother of Violet and Mira Sorrengail
Brennan Sorrengail is named in Fourth Wing, the first book of Rebecca Yarros's Empyrean series. He is the brother of Violet and Mira Sorrengail and the son of General Lilith Sorrengail. His rank and his dragon are spoilers that the guides list without saying which book reveals them, so we mark them as whole-series spoilers and fold them below, each with the fan guides, at least two, that agree on it.
Brennan first appears in Fourth Wing, book one of the series.
No spoilers Listed by theBookFeed and Esta Pinto (both opened Oct 14, 2026)
Violet and Mira Sorrengail are his sisters.
No spoilers Listed by theBookFeed and Empyrean Riders (both opened Oct 14, 2026)
His mother is General Lilith Sorrengail.
No spoilers Listed by theBookFeed and Empyrean Riders (both opened Oct 14, 2026)
His rank is lieutenant colonel.
Spoilers for the whole series Listed by theBookFeed and Empyrean Riders (both opened Oct 14, 2026)
His dragon is Marbh.
Spoilers for the whole series Listed by theBookFeed, Empyrean Riders and Esta Pinto (all opened Oct 14, 2026)
These facts come from unofficial fan guides, not the author or the publisher. A fact is shown only when two sites with different owners state the same thing; we write every sentence ourselves and quote nothing.