It was in accordance with this routine that the Commons commenced proceedings against the Earl of Strafford, very soon after the opening of the session, by appointing a committee to inquire whether there was any just cause to accuse him of treason. The committee reported to the House that there was just cause. The House then appointed a messenger to go to the House of Lords, saying that they had found that there was just cause to accuse the Earl of Strafford of high treason, and to ask that they would sequester him from the House, as the phrase was, and hold him in custody till they could prepare the charges and the evidence against him. All these proceedings were in secret session, in order that Strafford might not get warning and fly. The Commons then nearly all accompanied their messenger to the House of Lords, to show how much in earnest they were. The Lords complied with the request. They caused the earl to be arrested and committed to the charge of the _usher of the black rod_, and sent two officers to the Commons to inform them that they had done so. [Sidenote: Usher of the black rod.] The usher of the black rod is a very important officer of the House of Lords. He is a sort of sheriff, to execute the various behests of the House, having officers to serve under him for this purpose. The badge of his office has been, for centuries, a black rod with a golden lion at the upper end, which is borne before him as the emblem of his authority. A peer of the realm, when charged with treason, is committed to the custody of this officer. In this case he took the Earl of Strafford under his charge, and kept him at his house, properly guarded. The Commons went on preparing the articles of impeachment. [Sidenote: 1641.] [Sidenote: Laud threatened with violence.] This was in November. During the winter following the parties struggled one against another, Laud doing all in his power to strengthen the position of the king, and to avert the dangers which threatened himself and Strafford. The animosity, however, which was felt against him, was steadily increasing. The House of Commons did many things to discountenance the rites and usages of the Episcopal Church, and to make them odious. The excitement among the populace increased, and mobs began to interfere with the service in some of the churches in London and Westminster. At last a mob of five hundred persons assembled around the archbishop's palace at Lambeth.[5] This palace, as has been before stated, is on the bank of the Thames, just above London, opposite to Westminster. The mob were there for two hours, beating at the doors and windows in an attempt to force admission, but in vain. The palace was very strongly guarded, and the mob were at length repulsed. One of the ringleaders was taken and hanged. [5] See view of this palace on page 133. [Sidenote: Arrest of Laud on the charge of treason.]