Herbert’s father was a younger son of the Montgomery branch of the family, who fought in the Low Countries during the Elizabethan wars. He married a local heiress, and served as a magistrate from 1600, and as sheriff in 1607-8.
Herbert was called to the bar in 1618, and in the following year he joined the Virginia Company as legal counsel, perhaps at the recommendation of Sir John Danvers*, the stepfather of his first cousin (Sir) Edward Herbert* of Montgomery.
Whatever his motives may have been in securing a seat, Herbert is not known to have done much in his first Parliament. He was named to the committee for the bill to ban the receipt of secret pensions from foreign powers (25 May), and was presumably the ‘Sir Edward Herbert’ included on a committee for the Wey river navigation bill (6 March), while - as a lawyer - he is likely to have been the ‘Mr. Herbert’ named to the committee for the informers’ bill (19 April). Finally, it seems likely that he was the ‘Mr. Herbert’ included on the committee ordered to draft an appeal to the king to confirm the Commons’ privilege of free speech (12 Feb.), although this could have been his distant relation William Herbert I, MP for Cardiff.
At the start of the 1625 Parliament, Herbert was named to the committee for privileges (21 June), and it is more likely that he, as a lawyer, rather than his academic cousin George Herbert, was named to committees for the alienations’ bill (25 June) and the larceny bill (6 August). However, he is not known to have contributed to the fractious debates which led to an early dissolution.
Herbert remained aloof from the early inquiries into the duke’s misdeeds, until 4 Mar., when he was included among a delegation sent to the Lords to question Buckingham about his detention of a French ship, the St. Peter of Le Havre, which had provoked a French trade embargo. The duke, meanwhile, was attempting to rebuild the Anglo-French alliance founded upon his master’s recent marriage to Queen Henrietta Maria, and Herbert was one of those who heard Pembroke and Archbishop Abbot appeal for a generous vote of supply on the afternoon of 7 March.
The Crown’s position improved over the Easter recess, when (Sir) Dudley Carleton* brought news of a diplomatic rapprochement with the French. However, on 20 Apr. Herbert reported the Commons’ decision that Buckingham’s impeachment should take precedence over supply. Though he did not play any substantive part in the formulation of charges, on 3 May he was appointed to present one of the allegations to the Lords, concerning Buckingham’s engrossing of multiple offices. This was Pembroke’s chief grievance against the duke, and on 8 May Herbert warned the Lords that Buckingham had ‘too much power to betray the state of he were false, and too little ability to do service if he used his best industry’.
At the end of May, Buckingham cocked a snook at his enemies by accepting yet another public office, that of chancellor of Cambridge university; Herbert reported the Commons’ decision to write to the university for an explanation (5 June). Three days later he was named to a committee appointed to draft yet another Remonstrance, this time about the king’s continued collection of customs duties before they had received parliamentary approval.
Buckingham avenged himself against many of his enemies in the summer of 1626, but chose to placate the Herberts: Pembroke was promoted, becoming lord steward of the Household, while his post as lord chamberlain went to his brother (Sir) Philip Herbert*, earl of Montgomery, whose son was engaged to Buckingham’s daughter. Pembroke’s affinity thus remained aloof from the campaign against the Forced Loan, while in 1627 Herbert himself received a modest slice of Court patronage, as he was appointed steward of the Marshalsea Court.
By the time Parliament reconvened in 1629, Buckingham had been assassinated, a development which improved the prospects of Pembroke’s affinity. One of the chief problems facing the Crown was the refusal of a growing number of London merchants to pay customs duties, which had still not been confirmed by Parliament. On 22 Jan. Herbert was named to a committee considering the plight of John Rolle*, an MP whose goods had been seized by customs officials while he was under parliamentary privilege. Herbert was named to chair the committee investigating this grievance on the following day, and except on 13 Feb., when he was granted leave to plead a case before the House of Lords as counsel for Lord Henry Clifford*, he remained closely involved with this dispute.
Herbert served as one of the counsel for John Selden when the latter was prosecuted in Star Chamber for his part in these tumults, and also pleaded for the puritan Henry Sherfield* during his prosecution for iconoclasm in 1633. However, his position at Court was not thereby threatened, as acceptance of these controversial briefs merely proved his usefulness as counsel. Indeed, when the Marshalsea Court was reorganized in 1630, he retained his position as steward.
Herbert continued to serve Charles at Oxford, under the patronage of Prince Rupert, but in the autumn of 1645, with Rupert in disgrace and the royalist cause unravelling, he declined the post of lord keeper, and was dismissed. He went into exile in Paris, where Charles II appointed him lord keeper in 1653, but he became involved in a plot to unseat Sir Edward Hyde†, and in the following year, when he learned that he was not to follow the Court to Germany, he resigned. He died in Paris on 28 Dec. 1657 (new style), apparently without leaving a will. All three of his sons sat in Parliament after the Restoration; none had any heirs.
