Charles's third parliament, to which Selden was returned as member for Ludgershall, Wiltshire, he and other liberal leaders met to concert their plan of action at Sir Robert Cotton's house in Palace Yard. Selden and Coke argued that the reassertion of the ancient laws of the country by which the liberty of the subject was secured must take the first place, and that until this was accomplished no progress could be made in the redress of grievances. This opinion prevailed.
Accordingly, when parliament met, Selden took a prominent part in the debates which arose on the question of habeas corpus; he was the chairman of the committee appointed to consider the precedents as to imprisonment without cause assigned. On 2 April 1628 he addressed the house on the question. On 7 April he, together with Coke and Littleton, laid before the House of Lords the resolutions of the commons on the subject, and delivered before the lords a speech in assertion of the liberty of the subject. These speeches of Selden, together with copies of the records cited, were ordered by the house to be entered on the journals, and liberty was given to the clerk to give out copies. They formed probably a kind of manual from which less learned members of the party might prepare speeches.
The records with which Selden had fortified his speech before the lords became the occasion of an angry controversy. Lord Suffolk was reported to have charged Selden with tampering with one of the documents cited, and to have added that Selden deserved to be hanged. These words were brought before the House of Commons, which on 17 April 1628 presented to the lords two charges against the earl. In the upper house Suffolk declared that he had never used the words. In the commons Sir John Strangways declared on his honour that the earl had used the words. On 8 April 1628 (the day following his speech before the lords) Selden spoke on the question of the billeting of soldiers, and on 11 April on the question of martial law. Numerous notes have been preserved of speeches against the pretensions of the crown made by him on later days in the session. On 5 June the king sent the house a message that it would be adjourned on 11 June, and in the angry debate which followed Selden spoke in favour of naming Buckingham. On 18 June he opposed the king's claim to the personal estate of a deceased bastard, and next day (19 June) he spoke on a bill for the restitution to his rights of Carew, son of Sir Walter Ralegh. On 26 June the house was prorogued.
The recess of 1628 was passed by Selden at Wrest, and there he occupied himself with his work on the Arundel marbles. In January 1629 parliament again assembled; on 22 Jan. Selden brought before it the case of Savage, who had been sentenced by the Star-chamber to lose his ears. On 12 Feb. he supported the petition of the printers and booksellers against Laud's interference with their trade. In the same month he took an active part in the discussion of the bill for tonnage and poundage. In the violent scene of 2 March with which that session ended, Selden addressed the speaker in words of grave warning.
On 4 March 1629, in consequence of the house's proceedings, nine members, among whom were Selden and Eliot, were conducted to the privy council sitting at Whitehall, and, without hearing, were committed to the custody of Sir Alan Apsley, the keeper of the Tower ('vir humanissimus,' as Selden describes him), for imprisonment during the king's pleasure. At the same time, under an order from the king and council, seals were placed on the papers of Selden, Eliot, and Holles. On 10 March the parliament was dissolved by the king. On 17 March the prisoners were examined, in the presence of certain privy councillors, by Sir Robert Heath, the attorney-general. Selden's account of his answers is somewhat vague, but they seem to have consisted of an unblushing denial of the real facts as to the part he had played in parliament (cf. Gardiner, History, vii. 80). During his imprisonment Selden was at first denied the use of books and papers—a deprivation very bitter to his studious nature. Subsequently, on his petition, this prohibition was relaxed, but not without vexatious conditions. On 6 May and 5 June the cases of Selden and some of his fellow-prisoners were brought before the court of king's bench on applications for a habeas corpus and for bail respectively, Selden, Valentine, and Holles sitting in court by their counsel, Littleton, the substance of whose argument had been prepared by Selden. In the result the prisoners were remitted to prison, to be produced in court after the long vacation. Their detention had, according to the evil practice of that age, been a subject of conference and of correspondence between the king and the judges. In a letter from the king to the judges of his bench (24 June 1629) Charles says, in evident reference to their appearance in court during the argument of their case, that he had heard that the prisoners 'had carried themselves unmannerly towards the king and their lordships;' and he intimates a desire that they
