Brooke’s great-grandfather was Reginald Brooke, the younger son of Thomas Brooke (returned for Dorset in 1413 and subsequently four times for Somerset) and Joan, suo jure Baroness Cobham. Reginald inherited an estate in Suffolk, where he settled, and Brooke’s cousin George sat for Eye in 1584. Brooke’s father was a younger son who made a fortune in the City and bought Cockfield Hall, with much other property in his native county, from Arthur Hopton† in 1597.
Brooke inherited his father’s estate in 1601. Two years later, evidently expecting Parliament to be summoned soon after James I’s accession, he wrote to the corporation of Dunwich, six miles from his home, requesting a seat. However, the borough offered one place to Valentine Knightley* and the other to one of the Stanhopes, almost certainly Sir Michael*, although it agreed to elect Brooke if Stanhope tried to nominate someone else.
As sheriff of Suffolk, Brooke was ineligible for election to the 1614 Parliament. There is no evidence that he sought election in 1620. He evidently had interests in the City of London, presumably inherited from his father, as the following year, ‘having great occasions from time to time to sojourn’ there, he acquired a great house in Walbrook as satisfaction for £3,000 due from one of his father’s old servants who had gone bankrupt.
Brooke was not re-elected the following year, but was returned again for Dunwich in 1628, possibly after a contest with Sir John Rous I*.
In March 1630 Brooke appeared before the Privy Council on a close warrant, for an unspecified offence, but he was allowed to return to the country four days later.
