Who is the addressee in the poem, To Sir Henry Wotton?

The recipient of this verse letter is Sir Henry Wotton, a friend of Donne's and a diplomat who served as secretary to Robert Devereux, 2nd Earl of Essex during the reign of Queen Elizabeth I. Essex was a favorite of the queen before the two began disputing toward the end of the sixteenth century, approximately the time this verse letter was written. Eventually, Essex instigated an unsuccessful rebellion against the English government in 1601, which led to his execution. Donne writes to Wotton to caution him about his involvement at court and the ambitious men who surround him – perhaps a nod to Essex himself.