Question: What military officer and later de facto ruler of Panama was pen pal of Sarah York?
Sentence (from "Trịnh Tùng"): Trịnh Tùng is the first official Trịnh Lord, although his father – Trịnh Kiểm – was de facto ruler of Dai Viet before him, Trịnh Kiểm never claimed himself as Trịnh Lord.
Relevant evidence: No