Conversation so far:
who was the first person to say sleep is the cousin of death
Thomas Sackville said, By him lay heavy Sleep, the cousin of Death in his poem Sleep.
who is thomas sackville
Thomas Sackville, 1st Earl of Dorset was an English statesman, poet, and dramatist.
did thomas sackville have a political career
Thomas Sackville, 1st Earl of Dorset was a Member of Parliament and Lord High Treasurer.

Question: what else did sackville write
Self-contained rewrite: what did thomas sackville write besides his poem Sleep