Now for ourself and for this time of meeting:
Thus much the business is: we have here writ
To Norway, uncle of young Fortinbras -
Who, impotent and bed-rid, scarcely hears
Of this his nephew's purpose, - to suppress
His further gait herein; in that the levies,
The lists and full proportions, are all made
Out of his subject: and we here dispatch
You, good Cornelius, and you, Voltimand,
For bearers of this greeting to old Norway;
Giving to you no further personal power
To business with the king, more than the scope
Of these delated articles allow.
Farewell, and let your haste commend your duty.
CORNELIUS & VOLTIMAND
In that and all things will we show our duty.
We doubt it nothing: heartily farewell.
Exeunt VOLTIMAND and CORNELIUS
Claudius I was emperor of Rome from 41 to 54 AD. His reign occurred between those of Caligula and Nero, two of the more spectacularly crazy Roman Emperors. Due to his marriage to his niece Agrippina the Younger, Claudius was lumped into the same category of Roman depravity. The novelist Robert Graves gave his reputation something of a redemption in his novels I, Claudius and Claudius the God. (These two were the basis of a very memorable BBC adaptation in the late 1970s.)
Agrippina the Younger was Empress of Rome from 49 to 54 AD, and one of the foremost women of the Julio-Claudian dynasty. Her son Nero became Emperor, and was particularly loathed for his behaviour (not least the apocryphal story of how he 'fiddled' while Rome burned.) Nero will appear in a reference during Act 3 - primarily in the context of how he is reputed to have murdered Agrippina. She is immortalised in a variety of stories - from opera and theatre to film and television.
The (doubtless essential) essay I mentioned is Patricia Parker's "Othello and Hamlet: Dilation, Spying, and the "Secret Place" of Woman." It's available in Russ McDonald's book Shakespeare Re-Read - The Plays in New Contexts. You can buy it here.