i. 381 ; Hist. Coll. iv. 480). In May 1647 he was placed on the standing committee for appeals from the visitors of the university of Oxford, and also was appointed one of the commissioners for the disbanding of the army. In June 1648 his house, Bradfield Hall, was occupied in his absence by a party of troops belonging to the army of the Earl of Warwick, who plundered it, and turned out his wife (Rushworth, Hist. Coll. iii. 1128, 1349, 1354, 1356, iv. 34-7, 122, 142-3, 187, 241, 244; Comm.Journ.ii.52,v.500; Hist.MSS. Comm. 6th Rep. App. p. 306b, 7th Rep. App. p. 596b ; Nalson, Coll. Affairs of State, i. 319, 321, 691; Parl. Hist. ii. 656, 680; Somers Tracts, iv. 363; Cobbett, State Trials, iv. 317-18; Cal State Papers, Dom. 1640-1, pp. 450-1 ; Clarendon, Rebellion, i. 235,524; Whitelocke, Mem. pp.59,62, 249,312,314).
Burnet (fol. i. 45) tells a strange story, which he says he had from Grimston a few weeks before his death, to the effect that in 1647 or 1648 Grimston charged Cromwell in the House of Commons with designing to coerce the parliament, and that Cromwell fell down on his knees and made a solemn prayer to God attesting his innocence, afterwards in a long speech 'justifying both himself and the rest of the officers, except a few that seemed inclined to return back to Egypt,' and that thus 'he wearied out the house, and wrought so much on his party that what the witnesses had said was so little believed that had it been moved Grimston thought that both he and they would have been sent to the Tower,' and that accordingly the matter was allowed to drop. This story is not corroborated by any independent evidence. Grimston presided over the committee appointed to investigate the escape of the king from Hampton Court in November 1647, was one of the commissioners to whom the conduct of the negotiations with the king during his imprisonment in the Isle of Wight was entrusted in August 1648, and with Hollis appears to have taken a leading part in that matter. Burnet (ib. fol. i. 44) says that he besought the king on his knees to make up his mind with all possible despatch, lest all chance of accommodation should be destroyed by the independents gaining the ascendency. He was among the members of whom the house was purged by Colonel Pride on 6 Dec. 1648, and was thought of sufficient importance to be imprisoned. He was, however, released on 30 Jan. 1648-9, on giving an engagement not to do anything to the disservice of the parliament or army. Accordingly,after signing a remonstrance against the acts of the Rump, he retired into private life, resigning the recordership of Colchester (6 July 1649), and devoting his leisure to the education of his children, with whom he travelled on the continent for a time, and also to the onerous task of translating and editing reports of his father-in-law, Sir George Croke. In 1656, however, he was returned to parliament for Essex, though he was not permitted to take his seat, whereupon he and ninety-seven others who were in like case published a remonstrance and 'appeal unto God and all the good people of England' against their exclusion (Whitelocke, Mem. p. 653).
On the abdication of Richard Cromwell (April 1659) Grimston was placed by Monck on the committee for summoning a new parliament, to which the title of keepers of the liberties of England was given, and on the readmission of the secluded members in the following February he was elected into the council of state. He was chosen speaker of the House of Commons in the Convention parliament on 25 April 1660. In this capacity it fell to him to answer the king's letter of 14 April, to wait on him at Breda, and to deliver an address to him in the banquetting hall, Whitehall, on the 29th. His oratory on the latter occasion was fulsome and servile in the extreme. Charles repaid his compliment by visiting Grimston at his house in Lincoln's Inn Fields on 25 June. In the following October Grimston sat on the commission which tried the regicides, and in November he was appointed master of the rolls. Rumour, ill authenticated, but in itself not improbable, says that he paid Clarendon 8,000l. for the place. He held the office of speaker only during the Convention parliament, but continued to sit for Colchester until the dissolution of 1681. He was appointed chief steward of the borough of St. Albans by the charter granted to the town in 1664. He took as a rule but little part in the debates of the Pensionary parliament; but the so-called bill for preserving the protestant religion of 1677, which was in reality an attempt to relax the laws against papists, excited his vehement opposition. His last recorded speech was on the popular side on the debate on the rejection of the speaker by the king in March 1678-9. He died of apoplexy on 2 Jan. 1684-5, and is said to have been buried in the chancel of St. Michael's Church, St. Albans, where, however, there is no monument to him (Whitelocke, Mem. pp. 334, 700; Parl. Hist. iii. 1240, 1247, 1548, iv. 28, 56, 57, 862, 1096; Bramston, Autobiogr., Camd. Soc., pp. 114, 162; Willis, Not. Parl. iii. 274; Lists of Members of Parliament (Official Return of) ; Ludlow, Mem. p. 359; Comm.Journ. v. 357, viii. 1, 174; Hist. MSS. Comm. 1st Rep. App. p. 56, 5th Rep. App. p. 204, 7th Rep. App. p. 462; Cal. State Papers, Dom. 1659-