Account of the arrest of George Ferrers
In 1542, George Ferrers, a Member of Parliament, was arrested for debt while the House of Commons was sitting. This interrupted the business of the House, so the Serjeant at Arms was commanded to have Ferrers released from prison. When the Serjeant went to demand Ferrers' release, the clerks and officers there physically resisted him, damaging the Serjeant's Mace in the fracas. This outraged the House of Commons, who declared that the Serjeant at Arms should have the power of arrest on the authority of the Mace. The Serjeant returned to release Ferrers and arrested the men who had defied his orders. This case was significant because Ferrers' arrest was a breach of Parliamentary Privilege which protects Members of Parliament.
This account of Ferrers' arrest is from William Cobbett's 'The Parliamentary History of England'.