Herbert’s great-grandfather, an illegitimate brother of the 1st earl of Pembroke (William Herbert†), had children by three mistresses. The son of one of these unions acquired a modest estate at Oldcastle, Monmouthshire by marriage, but the family may have lived beyond their means, as in 1595 the future MP and his father were forced to mortgage property to pay off £600 worth of debts. The mortgage was never redeemed, and there may be some truth in the later allegation that Herbert’s father ‘became much decayed in his estate and did live in need and want (which continued till his death)’.
Presumably forced to seek a living elsewhere because of his dwindling prospects in Monmouthshire, Herbert took service with George Home, earl of Dunbar at some time during the early years of James’s reign, probably upon the recommendation of his father’s second cousin, the 3rd earl of Pembroke. He received a salary of £100 a year, and when Dunbar died in January 1611 the earl of Dunfermline, lord chancellor of Scotland, recommended Herbert to lord treasurer Salisbury (Robert Cecil†) for further preferment. As Dunbar’s only daughter was then contracted to marry Theophilus Howard*, Lord Walden, it was logical that the latter’s father, lord chamberlain Suffolk, should acquire Herbert’s services, and in 1612-13 Herbert and another of Suffolk’s servants, Meredith Morgan*, acted as the earl’s trustees in an important grant of Crown lands. Herbert was returned to Parliament in 1614 under the patronage of the Howard family, securing a seat at Morpeth, a borough controlled by Suffolk’s brother Lord William Howard.
Herbert probably left Suffolk’s service when his master was disgraced in 1618, which may explain why he chose this moment to launch a Chancery suit to recover the lands his father had mortgaged away in 1595. Fortunately for him, Herbert had acquired some independent means by the time of Suffolk’s fall. After Dunbar’s death his annual allowance of £100 had been replaced by a life annuity of 100 marks from the Crown, and by 1615 he was receiving another £100 a year as a gentleman pensioner, a post he doubtless secured at the recommendation of Lord Walden, captain of the band of pensioners until 1626.
Herbert probably chose not to stand again at the 1626 general election, as he was by this time deeply involved in litigation over his wife’s inheritance. In 1620 he married the daughter of Peter Bland, serjeant skinner [i.e. furrier] to the Crown. Although the bride was a widow who held property in St. Paul’s churchyard worth £150 a year in her own right, and lands in Warfield, Berkshire as a jointure from her first husband, her father took the unusual step of offering Herbert a second dowry. This apparent generosity contained an element of calculation, as the £2,000 Bland offered Herbert formed part of a longstanding debt of £5,000 he was owed by the Crown. Herbert apparently obtained an Exchequer warrant for payment, but Bland died before this could be redeemed, and after his decease a scrivener named Lawrence Lownes, who had married Bland’s niece, produced a deathbed will which he claimed Bland had drafted, with his assistance. Predictably, this testament made no mention of the bequest to Herbert, unlike Bland’s previous will, and on 7 Feb. 1628, after two years of litigation Herbert obtained a Chancery decree for payment of the £2,000 he was owed.
Following his defeat in Chancery, Lownes took his case to the Commons, where a bill to reverse the decree was tabled on 18 Apr. 1628. It received a second reading on 10 May, but failed to emerge from committee before the prorogation.
Little is known about the latter part of Herbert’s life. In 1637 he was involved in further litigation about Bland’s estate with his wife’s brother-in-law Thomas Langhorne, who had succeeded to the post of serjeant skinner, and in the following year he was consulted by Evan Edwards* over a grant of the keepership of Flint Castle. Returned to the Short Parliament for Christchurch, Hampshire on the recommendation of Theophilus, 2nd Lord Baltimore, he does not appear to have sought election to the Long Parliament, when Baltimore’s recommendation went to a Dorset lawyer, Matthew Davies†.