Two Labour peers caught up in the "cash for amendments" affair tonight became the first members of the upper chamber to be suspended in more than 350 years.
Voting was unanimous to bar Lord Truscott and Lord Taylor of Blackburn until the end of the Parliamentary session.
The pair were found guilty of breaching the Lords' code of conduct which requires members to "always act on their personal honour".
They were found to have offered to try to change the law in return for money.
Suspending a peer is a process so rarely used that the Committee sought legal advice about whether it was actually possible.
The last member of the upper house to be suspended was Viscount Savile, who was barred in 1642 for siding with King Charles I.
The move follows the resignation yesterday of Commons Speaker Michael Martin - the first case of a Speaker being forced out since 1695.
Attorney General Baroness Scotland tonight warned peers of the "constitutional enormity" of the move.
She added: "It is open for this House to do so, but this House has to consider whether these changed times entitles the House, obliges the House, to act differently".
Lord Truscott and Lord Taylor of Blackburn were found guilty of breaching the Upper House's rules by the Committee For Privileges.
Chairman of Committees Lord Brabazon of Tara, presenting the findings, said: "This episode has done serious damage to the reputation of the House.
"We all have responsibility individually and collectively to uphold that reputation.
"That is why personal honour remains the cornerstone of the House's code of conduct.
"Lord Truscott and Lord Taylor of Blackburn have not, we believe, acted on their personal honour."
He also defended the Committee's recommendation that the pair should be suspended, saying it was was necessary "to get our House in order".
The controversy was triggered by a Sunday Times investigation which claimed four Labour peers had told undercover journalists that they were willing to amend a Bill in return for money.
The other peers implicated in the affair, Lord Moonie and Lord Snape, were cleared of wrongdoing but ordered to apologise to the Lords.
Only Lord Snape was in the Lords to listen to the Committee's findings being debated.
Lords Leader Baroness Royall of Blaisdon said it was important for peers to agree the suspensions to uphold the "integrity" of Parliament.
Also highlighting the expenses scandal in the Commons, she told peers: "Politicians have plunged Parliament to the low in which we find ourselves."
She added: "We have not as politicians been doing our jobs in the way that people would want us to, with honesty, integrity and with honour."
Lady Royall told peers: "I believe that during the course of this inquiry... members of this House felt damaged and diminished by the conduct of members of this House," she said.
"I have had members of this House come to me and tell me what this time has meant - being shouted at in the street, their spouses reluctant to go to their local community for fear of what people will say."
Tory peers' leader Lord Strathclyde said: "The public expects this House will act with firmness and unity to show its abhorrence of wrongdoing and any propensity to it."
Lord McNally, for Liberal Democrats, said: "I still believe that those who serve both in the Lords and Commons are in the main motivated by a commitment to worthy ideas and ideals and that our public life is still relatively free from corruption, but protecting that honour requires eternal vigilance and where necessary, firm action."