A source of disappointment to his father, both for his impecunious habits and Civil War allegiance, Rich spent the greater part of his adult life anticipating his inheritance. Born in 1611 at Hackney, Middlesex, where he was also baptized, he was nominally enrolled at Gray’s Inn in August 1619 at the tender age of eight following his father’s succession to the earldom of Warwick. After being created a knight of the Bath at Charles I’s coronation, Rich was admitted to his father’s former college of Emmanuel, Cambridge, where he was awarded an MA. In January 1629, aged 17, he was returned to the third Caroline Parliament for Essex on Warwick’s interest at a by-election following the death of Sir Francis Barrington. Soon after taking his seat he and 11 other Members were appointed to take a message to the king concerning Charles’s request to expedite the Tunnage and Poundage bill (31 Jan.), but this was his only committee nomination.
Rich probably toured the Continent during the early 1630s, as he returned to England from Paris with news from the French Court in February 1632.
Elected to Parliament for Essex for a second time in October 1640, Rich was summoned to the Lords in January 1641, but was impeached in the following year for joining the king at York.
