Question: When did Thomas Sackville, 1St Earl Of Dorset's father die?
Sentence (from "Edmund Beaufort, 2nd Duke of Somerset"): He also succeeded in the title of 4th Earl of Somerset and was created 1st Earl of Dorset and 1st Marquess of Dorset( previously held by his father and later forfeited), and Count of Mortain.
Relevant evidence: No