The State Opening of Congress?
At the beginning of each new session of the Westminster Parliament, there is an event known as the State Opening of Parliament. Her Majesty proceeds from Buckingham Palace to Westminster, changes into her imperial regalia, and ascends the throne in the House of Lords. At this point, the Gentleman Usher of the Black Rod (the House of Lords’s equivalent to the House of Commons’s sergeant-at-arms) is sent to summon the Commons to attend upon Her Majesty and to hear the Queen’s Speech (which is, of course, written in its entirety by the Cabinet). When Black Rod arrives at the Commons’s chamber, the door is slammed in his face. He then knocks three times with his staff of office, at which point the door is opened and the Commons follow Black Rod to the Lords to hear the speech. You can see video of the whole thing here. The point, of course, is to symbolize the Commons’s independence from both Crown and Lords.
For some reason, recent events in the United States have put me in mind of this practice .