Edward Monagu: The Earl of Sandwiche.
But more seriously and briefly
Tanner calls Montagu, "the architect of [Pepys's]... fortunes" (14).
Trease says,
it is likely that without [Montagu]... Pepys would never have been in a postion to make some of its most interesting entries, especially his eye-witness accounts of critical moments in history.
Montagu was his first cousin once removed, his elder by seven and a half years, though at this age gap between them must have felt infinite. For in 1643, when the ten-year-old Pepys was learning his Latin declensions, the eighteen-year-old Montagu--in spite of a Royalist father--was raising his own parliamentry regiment, with which he soon distinguished himself at Marston Moor and Naseby.
(9-10)