Question: When did Nguyễn Phúc Miên Bửu's father die?
Sentence (from "Thừa Thiên (empress)"): Empress Thừa Thiên( 1762–1814), born Tống Phúc Thị Lan( 宋福氏蘭), was the first wife of Nguyễn Phúc Ánh( future Emperor Gia Long) and mother of Crown Prince Nguyễn Phúc Cảnh.
Relevant evidence: No