The L&M Companion has no biography about Mr. Cooke, but he is clearly a trusted servant to Sandwich.
Cooke first enters the Diary as one of the consistent official couriers between Montagu and Monck, making the trip from London to Deal in about 8 hours with the mail. (I therefore conclude he was fairly young.)
Other couriers were Sir “Peter the Post” Killigrew.
Jack Noble (a servant to John Pepys Snr. The L&M Index describes Noble as "a rogue." How does a tailor get his servant used for official dispatches on such a delicate subject?)
A Mr. Donne -- L&M Companion suggests he was Thomas Dunn, of Ratcliff, a ship's master in 1666; or Thomas Danes, an Admiralty messenger.
There are multiple entries about Mr. Cooke (no first name ever given, but always Mr.) taking and bringing the mail. Of more interest are:
On 8 May 1660 Pepys says Mr. Cooke brought him word about Elizabeth. He had been to Huntsmore, and escorted her and "father" Bowyer to London, where he left her at John Pepys Snr.’s house. She spoke to him of her love for Pepys.
(I therefore conclude Cooke was a familiar colleague at least to Pepys, possibly from living under Montagu's roof at the same time in the past?)
On 6 June 1660 Mr. Cooke arrived from London after dinner, bringing much interesting mail. He had left Elizabeth at Huntsmore, although her health not so constant as it used to be, which troubled Pepys.
(These repeated trips to Huntsmore must have been made with Montagu's knowledge and approval.)
On 12 June 1660 Pepys records "To my Lord’s [at Lincoln’s Inn Fields] and staid till 12 at night about business. So to my father’s, my father and mother in bed, ... But I found Mr. Cooke there, and so to bed."
(Sounds like Mr. Cooke is staying with Pepys' parents now, and was burning the midnight oil.)
On 18 July, 1660: "This morning we met at the office: I dined at my house in Seething Lane, and after that, going about 4 o’clock to Westminster, I met with Mr. Carter and Mr. Cooke coming to see me in a coach, and so I returned home."
(L&M Companion: Charles Carter, a near contemporary of Pepys at Magdalene, taking his B.A. in 1652; Rector of Irthlingborough, Northants. 1664-1675. His living or curacy in Huntingdonshire has not been traced. He was a native of Earith, Hunts.)
(What would place Cooke and Carter in a coach to search for Pepys at Westminster?)
However, on 23 July, 1660, just as Pepys secures his position as Clerk of the Acts, he records: "I was troubled all this day with Mr. Cooke, being willing to do him good, but my mind is so taken up with my own business that I cannot."
The trusted messenger wants his rewards as well.
Chart showing the number of references in each month of the diary’s entries.