Sentence:  ... Wilt thou know / Th' effect of what I wrote? ... / An earnest conjuration from the King, / As England was his faithful tributary, ... / That, on the view and knowing of these contents, / Without debatement further, more or less, / He should the <WSD>bearers</WSD> put to sudden death, 
Meaning of the word marked with <WSD> tags:  Someone who delivers a letter or message on behalf of another ("especially as referred to in the letter or message").