Edward VI's new privy council of twelve. Herbert and Sir Anthony Denny rode in the chariot carrying the coffin at Henry VIII's funeral.
Herbert supported the election of Seymour as protector on Edward VI's accession. On 10 July 1547 the young king granted him the manors of North Newton and Hulcot, and in the following year he was made master of the horse and a knight of the Garter. When disturbances broke out in 1549 in the west of England, he raised a force of two thousand Welshmen from his Welsh estates, and with Lord Russell relieved Exeter, which was threatened by an irruption of Cornishmen. His own park at Wilton had been invaded earlier, and he had dealt severely with the rioters. To repay him the heavy expenses of the campaign, the council allowed him to take the profits of minting two thousand pounds of bullion silver, which are said to have amounted to 6,709l. 19s.
Meanwhile the quarrel between Protector Somerset and his rival Warwick [see Dudley, John, Duke of Northumberland] had come to an open rupture. Both were anxious to gain Herbert's support. Somerset entreated him to bring his Welsh followers to his aid in London, while Warwick warned him that Somerset was engaging in treasonable practices. Herbert informed Somerset that his forces were still required to meet the rebels in the west (8 Oct.), and thenceforth acted with Warwick. On 8 April 1550 he was appointed president of Wales, and held the post till the end of the reign. On 9 July 1550 he took part in the examination of Gardiner, bishop of Winchester, and on 20 Dec. 1550 was allowed to maintain a hundred horsemen. In April 1551 Somerset made a new attempt to gain Herbert's support, but Herbert declined his advances. Herbert, Warwick, and Northampton had become supreme in the king's council, and Somerset seems to have meditated the forcible capture of the triumvirate. But Warwick was too powerful. Somerset was thrown into the Tower, and Warwick became undisputed dictator. Herbert, who took part in Somerset's trial, 1 Dec. 1551, was richly rewarded for his acquiescence in Warwick's promotion. He was raised to the peerage as Baron Herbert of Cardiff (10 Oct.) and Earl of Pembroke (11 Oct. 1551). He received Somerset's Wiltshire estates, including Ramsbury and a newly built mansion at Bedwin Broil, and much woodland on the borders of the New Forest (7 May 1553). He was also granted, on Sir Thomas Arundel's attainder, Wardour Castle and park, and obtained some property belonging to the see of Winchester. The Wardour property subsequently reverted to the Arundel family by exchange and purchase, but Pembroke's increase of wealth exceeded that of any of his colleagues. He was in attendance on the queen-dowager of Scotland when she visited London in November 1551, and on 21 Dec. he and Northumberland took the great seal from the custody of Lord-chancellor Rich (Wriothesley, Chron. ii. 61). In April 1552 he resigned the office of master of the horse to Northumberland's eldest son. In June 1552 he accompanied the king in his progress through the west with fifty horsemen, and on 28 Aug. 1552 conducted him to Wilton, where Edward stayed the night. In October rumours were spread that Pembroke and Northumberland had quarrelled, and these were repeated in April, but there was no outward sign of dissension. Pembroke arranged the marriage of his eldest son Henry to Lady Catherine Grey on the same day (21 May 1553) as Lady Jane Grey was married to Northumberland's son, Guildford, and he acted with Northumberland in all the negotiations for securing Lady Jane Grey's succession to the throne on Edward's death. He signed the engagement of the council and the letters patent confirming Jane's claims. According to Northumberland's account, Pembroke was the original deviser of the whole conspiracy, and was moved by a personal dread of losing his property if a Roman catholic sovereign should ascend the throne.
Throughout Lady Jane's short reign Pembroke was with her and Northumberland at the Tower of London, but when Northumberland left London to meet Mary's forces in the eastern counties, Pembroke declared for Mary, and was with the lord mayor when her proclamation was read in Cheapside (19 July). On Mary's arrival at the Tower her advisers regarded his attitude as ambiguous. He was directed to confine himself to his house at Baynard's Castle. On 8 Aug., however, he acted as one of the chief mourners at Edward VI's funeral; on 13 Aug. was appointed a privy councillor, and on 1 Oct. attended Mary's coronation. On the outbreak of Wyatt's rebellion the queen again entertained suspicions of his loyalty. But after some hesitation she allowed him to take chief command of the army gathered in London to resist Wyatt's entry. He placed his cavalry at what is now the Piccadilly end of St. James's Street, and his infantry at Charing Cross (9 Feb. 1553-4); but his troops made so slight a resistance to Wyatt's passage from Hyde Park to Ludgate Hill, that Pembroke's good faith was once more questioned. After the capture and execution of Wyatt general
