The State Opening of Parliament marks the start of a new parliamentary session, and usually takes place once a year. It may occur additionally when Parliament assembles after a general election.
Traditions surrounding the State Opening and delivery of a speech by the Monarch can be traced back at least to the 16th century, but the modern ceremony dates from the opening of the new Palace of Westminster in the mid-nineteenth century.
The Parliamentary Archives holds records relating to State Openings in several of its collections, including that of the Lord Great Chamberlain. A sample is provided here, with a focus on State Openings in the nineteenth and early twentieth centuries.