Fourth Wing (The Empyrean, Book 1)

US precedes: Red Tower Books (Entangled) is the originating publisher and the 2 May 2023 US hardcover is the true first. There is no original-language or foreign precedence question — the book is American and English-language. Piatkus (Little, Brown UK) issued the UK editions in 2023, collected as the first UK; sources consulted did not agree on the exact Piatkus release date, so no day-level UK claim is made here. UK variants in the trade include a Waterstones exclusive (ISBN 9780349441573, black boards, gilt spine titling, map endpapers, stencilled edges on all three sides) and a 2024 Piatkus paperback (9780349437019) — "first thus" only.