The Queen and Duke of Edinburgh were shown around a £19 million state-of-the-art resource centre.
Her Majesty officially opened The Keep, near Falmer, which will provide a home for archives and historical resources of East Sussex and Brighton and Hove.
Archivists showed the royal delegation maps of Sussex from 179, historic pictures of Eastbourne before it became a resort.
- Councillor in court over attempted murder of his wife
- Families fear Portslade playground has been 'forgotten’ by Brighton and Hove City Councillors
- Katie Price says there are "just too many roadworks" in Brighton
- Nine shipping containers to house businesses
- Rugby fans wait for world cup tickets set to end
Other achived included photos of Brighton Carnival stretching along Madeira Drive and its oldest document, Battle Abbey Charter, from 1101.
Senior Archivist Chris Whittick said: “They both showed a great interest in what he had shown them and they made most perceptive comments.
“We tried to select documents that would be of interest but not too personal. I think we got the right balance.”
Around two hundred royal watchers waited at Woollards Field, Moulsecoomb, for the royal cavalcade to arrive.